Material search method, material search system, program, and recording medium

Abstract

Provided are a novel material search method and a novel material search system. From among a plurality of peaks that occur in an XRD profile of an input sample, P peaks are acquired in order of greatest peak intensity. A record that includes R peak positions in order of greatest peak intensity is generated for each set of physical properties data of a plurality of known materials registered in a material database. From among a plurality of records, a record that includes peaks that match or substantially match all of the P peak positions of the sample is searched, and when a corresponding record is found, a determination is made as to whether the sample matches a known material that is registered in the material database. At least a portion of information pertaining to the known material is also outputted. Preferably, R is greater than P, and R is no more than 6 times P.

Description

Material search method, material search system, program, and recording medium

[0001] One aspect of the present invention relates to a material search method, a material search system, a program, and a recording medium.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. The technical field of the invention disclosed in this specification relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition of matter.

[0003] In recent years, various materials, such as inorganic and organic materials, have been actively developed in various technical fields. One known method for evaluating material properties is an analytical method using X-ray diffraction (XRD) (also referred to as "XRD analysis"). Examples of XRD analysis include powder X-ray diffraction, which can nondestructively evaluate crystallinity and orientation, and identify or estimate materials. In particular, powder X-ray diffraction is widely used as a method for analyzing polycrystalline bodies.

[0004] In XRD analysis, a sample is irradiated with X-rays of a fixed wavelength while changing the angle of incidence, and the intensity of the reflected X-rays is measured to obtain a diffraction pattern specific to the material (also called "2θ / θ measurement," "2θ / ω measurement," or "out-of-plane measurement").The obtained diffraction pattern (also called "XRD profile," "XRD spectrum," or "powder pattern") can reveal the elements that make up the sample, its crystallinity, orientation, and so on.

[0005] XRD analysis is one of the techniques used to analyze the crystalline structure of positive electrode active materials. XRD data can be analyzed using crystalline structure data stored in the Inorganic Crystal Structure Database (ICSD) introduced in Non-Patent Document 1. For example, the lattice constant of lithium cobalt oxide described in Non-Patent Document 2 can be referenced from the ICSD.

[0006] On the other hand, XRD analysis requires advanced expertise such as crystallography to analyze diffraction patterns and identify materials, and analysis takes time.

[0007] As examples of material identification using diffraction patterns, there have been proposed a method of searching a database (e.g., Hanawalt index) for a substance based on the positions of three intense peaks (which may be indicated by interplanar spacing), a method of setting an error window around the peak positions and relative intensities and determining whether or not the peak positions and relative intensities in the ICDD-PDF file match or mismatch based on whether they are within the error window, and a determination method based on probability theory (SANDMAN (Search and Match Nova)).

[0008] Belsky, A. et al. , “New developments in the Inorganic Crystal Structure Database (ICSD): accessibility in support of materials research and design”, Acta Crystal. , (2002) B58 364-369. Akimoto, J. ; Gotoh, Y.; ; Oosawa, Y.; “Synthesis and structure refinement of LiCoO▲2▼ single crystals” Journal of Solid State Chemistry (1998) 141, p. 298-302.

[0009] However, general XRD databases and analysis software contain a large amount of data from various technical fields, and search methods using these have the problem of selecting too many candidate substances (also called "candidate materials"). Furthermore, software for analyzing diffraction patterns is often built into XRD analysis equipment, limiting users' opportunities to use it. Furthermore, while it is possible to narrow down the search by composition, there is also the problem that it is not always possible to search from a database in the technical field that suits the purpose.

[0010] For example, XRD analysis is widely used in the field of lithium-ion batteries for material synthesis and degradation analysis, etc. However, data analysis has been difficult for engineers who do not necessarily have expertise in crystallography.

[0011] In particular, lithium-ion batteries use electrodes (also called "composite electrodes") that are made by mixing active materials, conductive additives, and binders, coating the current collector, and pressing them. Analysis of composite electrodes is more difficult because multiple materials are mixed together, and the active materials become oriented when pressed to increase the electrode density.

[0012] Therefore, there was a need for a system that allows users to create a database to be used for searching and that allows easy analysis on any computer without using the software built into the XRD analyzer. Furthermore, since a large number of candidate materials are displayed after a search, which is undesirable for non-expert users, it is desirable to display only one candidate material. Furthermore, when selecting candidate materials automatically, the presence of impurity phases can sometimes hinder accurate selection, so it is desirable to be able to search the material database by peak position and peak range.

[0013] An object of one embodiment of the present invention is to provide a material search system that allows a material search to be performed without advanced specialized knowledge.An object of one embodiment of the present invention is to provide a material search method that allows a material search to be performed without advanced specialized knowledge.An object of one embodiment of the present invention is to provide a material search system with reduced cost.An object of one embodiment of the present invention is to provide a material search method with reduced cost.An object of one embodiment of the present invention is to provide a novel material search method.An object of one embodiment of the present invention is to provide a novel material search system.

[0014] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract other problems from the description of the specification, drawings, claims, etc.

[0015] One aspect of the present invention is a material search method and material search system that realizes low-cost and accurate material (substance) search using an XRD profile obtained by 2θ / θ measurement, which is a common technique in XRD analysis.

[0016] Here, we will explain 2θ / θ measurement in XRD analysis. 2θ / θ measurement is a technique in which X-rays are incident on a sample at an angle θ relative to the horizontal and the intensity of the reflected X-rays is detected at an angle 2θ relative to the horizontal. The intensity of the reflected X-rays is detected at 2θ positions while varying the incident angle θ. By analyzing the XRD profile, which shows the intensity of the reflected X-rays relative to changes in 2θ values, it is possible to evaluate crystallinity and orientation, estimate the material, and more. For example, the constituent material of a sample can be estimated from the position and intensity of peaks that appear in the XRD profile. Estimating the constituent material of a sample is sometimes referred to as identification. Note that XRD analysis is not limited to 2θ / θ measurement. For example, there is also 2θ measurement. 2θ measurement is a technique in which the incident angle of X-rays irradiated on a sample is fixed and the intensity of the reflected X-rays is measured while varying the position of the detector. Furthermore, because θ and 2θ are angles, the units of θ and 2θ may be expressed in this specification as "degree," "deg.", "degree," or "°."

[0017] When analyzing a polycrystalline sample (e.g., a solid or powdered sample), multiple peaks specific to the material appear in the XRD profile. The constituent materials of a crystalline sample can be estimated using the positions and intensities of the peaks that appear in the XRD profile and a materials database containing physical property data of known materials. Users may freely add or delete data from the materials database. By excluding materials that the user does not handle or is not sure to include from the materials database, estimation can be made more reliably.

[0018] Specifically, the material database is searched using the positions and intensities of peaks appearing in the XRD profile of the sample as clues. When searching the material database, it is difficult to determine a matching or approximately matching material using only one of the multiple peaks appearing in the XRD profile. Therefore, materials are searched using multiple peaks appearing in the XRD profile. The multiple peaks used in the material search are determined in descending order of peak intensity. In this specification and elsewhere, "peak intensity" refers to the height of the peak.

[0019] In one embodiment of the present invention, for example, the three peaks in descending order of peak intensity are used to search for materials constituting a sample. Specifically, the peak with the highest peak intensity is designated the first peak, the peak with the second highest peak intensity is designated the second peak, and the peak with the third highest peak intensity is designated the third peak. The positions of the first to third peaks are compared with the peak positions of known materials registered in a materials database to determine whether or not physical property data matches or approximately matches that of the sample. Note that the positions of the peaks appearing in the XRD profile are defined by the value of 2θ.

[0020] The intensities of the multiple peaks appearing in an XRD profile may be subject to errors due to the condition of the sample and the installation state of the sample, resulting in the peak intensity order being reversed. For example, a peak that should be determined to be the second peak may be determined to be the third peak. Therefore, if the peak intensity order is strictly applied to determine whether a material matches or approximately matches the sample, accurate material detection becomes difficult. Therefore, conventional methods such as the Hanawalt method may present a large number of search result candidates. As a result, an inexperienced operator may not be able to determine which is the correct search result.

[0021] For example, LiCoO, which is commonly used as a positive electrode active material, ２ is non-oriented LiCoO ２In the case of powder, the first peak is a reflection from the (003) plane and the second peak is a reflection from the (104) plane, but if the material is oriented in the (001) plane, the reflection from the (003) plane of the first peak may be significantly stronger than the reflections from other planes, and the second peak may be a reflection from the (006) plane. In such cases, comparing the intensity ratios with those in the materials database may result in an inaccurate search.

[0022] For example, a material search for a sample can be performed using the following method. First, among the multiple peaks appearing in the XRD profile of the input sample, the peak positions of P peaks in descending order of peak intensity are obtained. Furthermore, for each of the physical property data of multiple known materials registered in the material database, a record containing the peak positions of R peaks in descending order of peak intensity is generated. A record containing peaks that match or approximately match all of the P peak positions of the sample is searched for from a dataset containing multiple records. If a matching record is found, it is determined that the known material associated with the record matches the sample. Then, at least some or all of the physical property data for the known material determined to match the sample may be output to a display device or externally. Note that P in the P list may be an integer between 2 and 10, and R in the R list may be an integer greater than P.

[0023] If multiple matching candidate materials are presented, the value of the relative difference E (detection range) used to determine whether the peak positions match may be decreased, and the process of searching again may be repeated until only one candidate is left. Alternatively, if no matching candidate materials are displayed, the value of the relative difference E may be increased, and the process of searching again may be repeated until only one candidate is left.

[0024] Furthermore, if a relatively strong peak is observed in the XRD profile that was determined to be a match but was not used in the determination, other candidate materials may be directly searched for using information such as peak position, peak intensity, and reflection surface in the material database.

[0025] Another aspect of the present invention is a material search method that uses an XRD profile and a first dataset, wherein the first dataset has a plurality of records each including R first peak positions extracted from physical property data of a plurality of known materials in descending order of peak intensity for each physical property data; the method identifies a plurality of second peak positions and intensities from the XRD profile of the first material; obtains P second peak positions in descending order of peak intensity from the plurality of second peak positions and intensities; searches the first dataset for records each including a first peak position that matches each of the P second peak positions; and, if a matching record is found, determines that the known material associated with the matching record is the same as the first material; P is an integer between 2 and 10, and R is an integer greater than P.

[0026] Another aspect of the present invention is a material retrieval system that uses an XRD profile and a first dataset, wherein the first dataset has a plurality of records each including R first peak positions extracted from physical property data of a plurality of known materials in descending order of peak intensity for each physical property data, and the material retrieval system has a function of identifying a plurality of second peak positions and intensities from the XRD profile of the first material, a function of acquiring P second peak positions in descending order of peak intensity from the plurality of second peak positions and intensities, a function of searching the first dataset for records each including a first peak position that matches each of the P second peak positions, and a function of determining, when a matching record is found, that the known material associated with the matching record is the same as the first material, wherein P is an integer between 2 and 10, and R is an integer greater than P.

[0027] R is preferably 6 times or less, more preferably 3 times or less, of P.

[0028] The record may also have R plane indices corresponding to the R first peak positions, respectively. The material retrieval system may have a function of calculating the lattice constant of the first material determined to be the same as that of the known material, using the first peak positions and the plane indices.

[0029] Another aspect of the present invention is a material search system using an XRD profile and a second dataset, the second dataset having a plurality of records, each record having a name of a material having a peak whose peak position falls within a specified range and the peak position, the material search system having a function of displaying the XRD profile on a display device, a function of displaying the second dataset on the display device, and a function of displaying a vertical marker on the display device indicating the peak position of a record selected from the second dataset. The peak of the record is preferably a peak whose relative intensity falls within the specified range. The vertical marker may be displayed superimposed on the XRD profile.

[0030] Another aspect of the present invention is a program for executing the above-described material search method on a computer, a program for realizing the above-described material search system on a computer, or a computer-readable recording medium on which the above-described program is recorded.

[0031] According to one aspect of the present invention, a material search system that allows a material search to be performed without advanced specialized knowledge can be provided. According to one aspect of the present invention, a material search method that allows a material search to be performed without advanced specialized knowledge can be provided. According to one aspect of the present invention, a material search system with reduced costs can be provided. According to one aspect of the present invention, a material search method with reduced costs can be provided. According to one aspect of the present invention, a novel material search method can be provided. According to one aspect of the present invention, a novel material search system can be provided.

[0032] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc.

[0033] FIG. 1A is a block diagram showing an example of the configuration of a material search system according to one embodiment of the present invention. FIG. 1B is a diagram showing an example of an XRD profile. FIG. 2 is a diagram showing an example of a material database and physical property data. FIG. 3 is a diagram showing an example of a data set and a record. FIG. 4 is a flowchart for explaining an example of the operation of the material search system. FIG. 5A is a diagram showing an example of an XRD profile. FIG. 5B is a diagram showing the peak positions of first to third peaks and the relative values ​​of peak intensities. FIG. 6 is a diagram comparing the peak positions of a sample with the peak positions registered in a record. FIG. 7 is a diagram showing an example of a search result displayed on a display screen of a display device. FIGS. 8A and 8B are flowcharts for explaining an example of the operation of the material search system. FIGS. 9A and 9B are flowcharts for explaining an example of the operation of the material search system. FIG. 10A is a diagram showing an example of a search result displayed on a display device. FIG. 10B is a diagram showing an example of a filter condition. FIG. 10C is a diagram showing an example of a data set. FIG. 11A is a diagram showing an example of a filter condition. FIG. 11B is a diagram showing an example of a data set. FIG. 11C is a diagram showing an example of a display screen. 12A to 12C are diagrams showing examples of filter conditions.

[0034] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same parts or parts having similar functions will be denoted by the same reference numerals in different drawings, and repeated explanations will be omitted.

[0035] Ordinal numbers such as "first" and "second" used in this specification are used to avoid confusion between components and do not indicate any order or ranking, such as the order of processes or stacking. Furthermore, even if a term does not have an ordinal number in this specification, an ordinal number may be added in the claims to avoid confusion between components. Furthermore, even if a term has an ordinal number in this specification, a different ordinal number may be added in the claims. Furthermore, even if a term has an ordinal number in this specification, the ordinal number may be omitted in the claims.

[0036] In this specification, space groups are expressed using short notation in international notation (or Hermann-Mauguin notation). Crystal planes and crystal directions are expressed using Miller indices. In crystallography, space groups, crystal planes, and crystal directions are expressed by placing a superscript bar above the number. However, due to formatting constraints, in this specification, instead of placing a bar above the number, a minus sign (-) may be placed before the number. Individual orientations indicating directions within a crystal are expressed using [ ], collective orientations indicating all equivalent directions are expressed using < >, individual planes indicating crystal planes are expressed using ( ), and collective planes with equivalent symmetry are expressed using {}. For ease of understanding the structure, trigonal crystals represented by the space group R-3m are generally expressed as a hexagonal composite hexagonal lattice. Unless otherwise specified, the space group R-3m will also be expressed as a composite hexagonal lattice in this specification. Miller indices may also be expressed as (hkl) rather than (hkil). Here, i is −(h+k). In this specification and the like, for the space group R-3m, crystal planes and the like are expressed as a composite hexagonal lattice unless otherwise specified.

[0037] First Embodiment In this embodiment, a configuration example and an operation example of a material searching system 100 according to one aspect of the present invention will be described.

[0038] 1A is a block diagram showing an example of the configuration of a material search system 100 according to one embodiment of the present invention. The material search system 100 includes a control device 110, an arithmetic device 120, a storage device 130, an auxiliary storage device 140, an input / output device 150, a communication device 160, and a display device 170. The respective devices are electrically connected via a bus line 101.

[0039] [Control device 110, arithmetic device 120] The control device 110 has a function of controlling the operations of the devices included in the material retrieval system 100. The arithmetic device 120 has a function of executing arithmetic processing related to material retrieval. For example, a central processing unit (CPU) can be used as the control device 110. For example, a CPU or a graphics processing unit (GPU) can be used as the arithmetic device 120.

[0040] The control device 110 and the arithmetic device 120 may also be realized by a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array) or an FPAA (Field Programmable Analog Array).

[0041] The calculation results obtained by the arithmetic unit 120 are displayed on the display device 170. The calculation results obtained by the arithmetic unit 120 are stored in the storage device 130 or the auxiliary storage device 140. The calculation results obtained by the arithmetic unit 120 are output to the outside via the input / output device 150 or the communication device 160.

[0042] [Storage Device 130] The storage device 130 has a function of storing programs and parameters related to the operation of the material retrieval system 100, and is preferably at least partially rewritable memory. For example, the storage device 130 can include a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a ROM (Read Only Memory).

[0043] The RAM provided in the storage device 130 may be, for example, a dynamic random access memory (DRAM). A part of the RAM is allocated as a memory space for the material retrieval system 100. The operating system, application programs, data, etc. stored in the auxiliary storage device 140 are loaded into the RAM for execution.

[0044] The ROM provided in the storage device 130 may be a mask ROM, an OTPROM (One Time Programmable Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), etc. Examples of the EPROM include a UV-EPROM (Ultra-Violet Erasable Programmable Read Only Memory), which allows stored data to be erased by ultraviolet light irradiation, an EEPROM (Electrically Erasable Programmable Read Only Memory), and a flash memory. The ROM can store a BIOS (Basic Input / Output System), firmware, and the like, which do not require rewriting.

[0045] [Auxiliary Storage Device 140] The auxiliary storage device 140 is a storage device for saving the operating system, application programs, data, etc. It may also store various parameters used by the arithmetic device 120.

[0046] The auxiliary storage device 140 may be, for example, a storage device using nonvolatile storage elements such as flash memory, MRAM (Magnetoresistive Random Access Memory), PRAM (Phase Change RAM), ReRAM (Resistive RAM), and FeRAM (Ferroelectric RAM), or a storage device using volatile storage elements such as DRAM (Dynamic RAM) and SRAM (Static RAM). Furthermore, a recording media drive such as a hard disk drive (HDD) or a solid state drive (SSD) may also be used.

[0047] Furthermore, for example, the auxiliary storage device 140 may be a storage device such as an HDD or SSD that is detachable via the input / output device 150. Also, a media drive for a computer-readable recording medium such as a flash memory, a Blu-ray Disc (registered trademark), a DVD, or a USB memory may be used as the auxiliary storage device 140.

[0048] When a storage device placed outside the material retrieval system 100 is used as the auxiliary storage device 140, the communication device 160 may be used to input and output data to and from the material retrieval system 100 via wireless communication.

[0049] [Input / Output Device 150] The input / output device 150 has a function of controlling the input and output of signals between external devices and the material retrieval system 100. The input / output device 150 may have an external port such as an HDMI (registered trademark) terminal, a USB terminal, or a LAN (Local Area Network) connection terminal. The input / output device 150 may also have a transmitting / receiving function for optical communication using infrared light, visible light, ultraviolet light, or the like. The input / output device 150 also functions as an interface for information input means such as a mouse, keyboard, pen tablet, and touch panel (touch sensor).

[0050] An example of an XRD profile of a material to be analyzed is shown in Figure 1B. The horizontal axis of the graph shown in Figure 1B represents 2θ (unit: degrees (deg.)) when Cu is used as the X-ray source, and the vertical axis represents intensity in arbitrary units (au). The XRD profile of the material to be analyzed is input to the material retrieval system 100 via the input / output device 150.

[0051] [Communication Device 160] The communication device 160 can perform communication via an antenna. For example, the communication device 160 controls a control signal for connecting the material retrieval system 100 to a computer network in response to an instruction from the arithmetic device 120 and transmits the control signal to the computer network. This allows the material retrieval system 100 to connect to and communicate with computer networks such as the Internet, intranet, extranet, PAN (Personal Area Network), LAN (Local Area Network), CAN (Campus Area Network), MAN (Metropolitan Area Network), WAN (Wide Area Network), and GAN (Global Area Network), which are the foundations of the World Wide Web (WWW). When multiple communication methods are used, the communication device 160 may have multiple antennas depending on the communication methods.

[0052] The communication device 160 may be provided with, for example, a high-frequency circuit (RF circuit) for transmitting and receiving RF signals. The high-frequency circuit converts between electromagnetic signals and electric signals in a frequency band defined by the laws of each country, and communicates wirelessly with other communication devices using the electromagnetic signals. A practical frequency band is generally several tens of kHz to several tens of GHz. The high-frequency circuit connected to the antenna has a high-frequency circuit section compatible with multiple frequency bands, and the high-frequency circuit section may be configured to include an amplifier, a mixer, a filter, a DSP (Digital Signal Processor), an RF transceiver, etc. When wireless communication is performed, communication standards such as LTE (Long Term Evolution), GSM (Global System for Mobile Communication: registered trademark), EDGE (Enhanced Data Rates for GSM Evolution), CDMA2000 (Code Division Multiple Access 2000), and WCDMA (Wideband Code Division Multiple Access: registered trademark), or specifications standardized by IEEE such as Wi-Fi (registered trademark), Bluetooth (registered trademark), and ZigBee (registered trademark), can be used as communication protocols or communication technologies.

[0053] The XRD profile of the material to be searched may be input to the material retrieval system 100 via the communication device 160 .

[0054] A computer including the control device 110, the arithmetic device 120, the storage device 130, the auxiliary storage device 140, and the input / output device 150 or the communication device 160 can function as the material retrieval system 100. For example, when a signal for starting a program according to one embodiment of the present invention is input to the control device 110 via the input / output device 150 or the communication device 160, the control device 110 outputs a signal for causing the storage device 130 to load the program stored in the auxiliary storage device 140. By loading the program into the storage device 130, the computer can function as the material retrieval system 100. Note that part or all of the program may be stored in ROM.

[0055] The control device 110 also outputs a signal to cause the storage device 130 to read various data, such as setting parameters, input via the input / output device 150 or the communication device 160. The arithmetic device 120 executes arithmetic processing using the programs and data loaded into the storage device 130. The auxiliary storage device 140 can also be used as the storage device 130. A cache provided inside the arithmetic device 120 can also be used as the storage device 130.

[0056] The program for causing a computer to function as the material search system 100 may be written in various programming languages ​​such as Python (registered trademark), Go, Perl, Ruby, Prolog, Visual Basic (registered trademark), C, C++, Swift, Java (registered trademark), JavaScript (registered trademark), or a markup language such as html (Hypertext Markup Language) in combination with a programming language. Alternatively, the program may be written in a style sheet language such as CSS (Cascading Style Sheets). In this specification, the programming language is understood to include markup languages ​​and style sheet languages.

[0057] Furthermore, the program for causing a computer to function as the material retrieval system 100 may include multiple programs written in the same programming language, or multiple programs written in different programming languages.

[0058] For example, multiple programs configured by function may all be written in the same programming language and combined to be used as a single program. For example, multiple programs may all be written in Python and combined to be used as a single program.

[0059] For example, some or all of multiple programs configured by function may be written in different programming languages, and the programs may be combined and used as a single program. For example, a program written in Python and a program written in JavaScript may be combined and used as a single program. Furthermore, for example, a program written in JavaScript may be written in HTML. HTML can be executed in various web browsers. Therefore, the material search system 100 can be realized on any computer.

[0060] [Display Device 170] Various display devices can be used as the display device 170. For example, a liquid crystal display device, a light-emitting display device having a light-emitting element such as an EL (Electro Luminescence) element in each pixel, or an electrophoretic display device can be used. Also, a display device such as a DMD (Digital Micromirror Device), a PDP (Plasma Display Panel), or an FED (Field Emission Display) can be used.

[0061] [Materials Database] The material search system 100 includes a materials database 141 that lists the physical properties of known materials. The physical properties of materials may be obtained using the Crystallographic Information File (CIF) published by the ICSD. Alternatively, the International Centre for Diffraction Data (ICDD), the National Institute of Standards and Technology (NIST), the Cambridge Structural Database (CSD), or the Powder Diffraction File (PDF) provided by the Pauling File may be used. Regardless of the above, the physical properties of materials may be obtained from various databases. Furthermore, the physical property values ​​of a material may be obtained not only from a database but also from simulation data. Furthermore, the physical property values ​​of a material may be data obtained by a user through experiments, etc. The physical property values ​​of a material may also be referred to as literature values, etc.

[0062] FIG. 2 shows an example of the material database 141 included in the material search system 100. While CIF and other data contain information on the crystalline structure of a material, such as its lattice constant and space group, they may not contain numerical data on the positions and relative intensities of each peak. In this case, the positions and relative intensities of each peak are calculated for each material, taking into account the wavelength of the X-ray source, and are added to the material database 141 as physical property data 142. Therefore, the material database 141 contains physical property data 142 for multiple materials. When using a material database that compiles physical property values ​​for each material, including numerical data on the positions and relative intensities of each peak, these values ​​may be added to the material database 141 as they are.

[0063] 2 shows the items to be registered in the material database 141, such as material name, space group number, plane index, plane spacing, peak position when Cu is used as the X-ray source, and peak relative intensity. Note that the material database 141 does not need to have all of these items, and may also have items other than these. Furthermore, multiple material databases may be prepared depending on the purpose, etc.

[0064] The material database 141 may be stored in the auxiliary storage device 140, or may be stored in a server 510 or a cloud system 520 connected by wired or wireless communication via the input / output device 150 or the communication device 160. The material database 141 may also be written in a program that causes a computer to function as the material search system 100. As a specific example, a Javascript sequence converted by Python may be embedded in HTML, and necessary data may be extracted from the sequence using Javascript, and the extracted data may be displayed as graphs and tables on the display device 170 using Javascript.

[0065] The program for creating the materials database 141 can be written in various programming languages ​​such as Python (registered trademark), Go, Perl, Ruby, Prolog, Visual Basic (registered trademark), C, C++, Swift, Java (registered trademark), and JavaScript (registered trademark).

[0066] The program for creating the material database 141 may include multiple programs written in the same programming language, or multiple programs written in different programming languages. For example, the material database 141 may be created by adding the physical property data 142 for each material using Python, or the material database 141 created using Python may be added with the physical property data 142 for each material using Javascript.

[0067] [Dataset] The material search system 100 includes a data set 146 in which information necessary for material search is extracted from the material database 141. The data set 146 is a collection of multiple records 145 generated for each piece of physical property data 142. An example of the data set 146 is shown in FIG.

[0068] The records 145 are generated by extracting R peak positions (R is an integer of 3 or more) in descending order of relative peak intensity for each piece of physical property data 142 included in the material database 141. The data set 146 shown in Fig. 3 is made up of a plurality of records 145 where R is 7. In other words, the data set 146 shown in Fig. 3 is made up of a plurality of records 145 each including information on seven peak positions (peak 1 to peak 7) selected in descending order of relative peak intensity.

[0069] The data set 146 may also include various information other than the peak positions. For example, it may include information on the plane indices hkl corresponding to the peak positions. By using these, the lattice constant of the estimated material can be calculated.

[0070] The number R of peak positions included in the record 145 will be explained in detail in the explanation of an example of the operation of the material retrieval system 100.

[0071] A search for materials matching the sample is performed using a dataset 146. If the constituent elements of the sample can be predicted in advance, the records 145 that make up the dataset 146 may be limited. For example, if a synthesized material is used as the sample and it is predicted that the sample is likely to contain Li, Co, and O (oxygen), the records 145 may be limited to cobalt oxide and lithium cobalt oxide-based materials, materials that are expected to be mixed in during material synthesis, and materials that contain the constituent elements of the equipment used during material synthesis.

[0072] By excluding records 145 that are not considered to be related to the sample from the data set 146 or excluding them from the search, the search speed and accuracy can be improved.

[0073] The records 145 included in the data set 146 may be generated by the user inputting peak positions. The records 145 may also be generated using information other than that in the material database 141. For example, peak positions obtained by theoretical calculations such as simulations may be input. The data set 146 may also be generated by the user collecting a predetermined number of peaks from the material database 141 in order of peak intensity.

[0074] In addition, in the material names in FIG. 3, Li (Ni ０．８ Co ０．１ Mn ０．１ ) O ２ is designated as "NCM811" and Li(Ni ０．６ Co ０．２ Mn ０．２ ) O ２ is shown as "NCM622". Also, Li (Ni ０．５ Co ０．２ Mn ０．３ ) O ２ is designated as "NCM523" and Li(Ni ０．３３ Co ０．３３ Mn ０．３３ ) O ２ is shown as "NCM333".

[0075] The program for creating the data set 146 may be written in the same programming language as the program for creating the material database 141, or in a different programming language. Furthermore, the program for creating the data set 146 may include multiple programs written in the same programming language, or multiple programs written in different programming languages. For example, the material database 141 may be created by adding physical property data 142 for each material using Python, or may be created by adding records 145 for each material using Javascript to the data set 146 created in Python.

[0076] The data set 146 may also be written in a program that causes a computer to function as the material retrieval system 100 .

[0077] The number of datasets 146 generated by the material retrieval system 100 is not limited to one. For example, multiple datasets 146 may be generated depending on the purpose or application. Of the multiple datasets 146, a frequently used dataset 146 may be stored in the storage device 130, and the other datasets 146 may be stored in the auxiliary storage device 140, the server 510, the cloud system 520, or the like.

[0078] <XRD Analysis Apparatus> Here, the XRD analysis apparatus will be described. There are no particular limitations on the XRD analysis apparatus and analysis conditions as long as the apparatus is properly adjusted and calibrated using a standard sample. For example, measurements can be performed using the following apparatus and conditions: XRD apparatus: D8 ADVANCE manufactured by Bruker AXS; X-ray source: Cu; Output: 40 kV, 40 mA; Divergence angle: Div. Slit, 0.5°; Detector: LynxEye; Scan method: 2θ / θ continuous scan; Measurement range (2θ): 15° to 90°; Step width (2θ): 0.01° setting; Counting time: 1 second / step; Sample stage rotation: 15 rpm. The standard sample used for adjustment and calibration can be, for example, a NIST standard aluminum oxide sintered plate SRM1976.

[0079] If the measurement sample is a powder, it can be set by placing it on a glass sample holder or sprinkling it on a greased silicone anti-reflective plate. If the measurement sample is a positive electrode, the positive electrode can be attached to the substrate with double-sided tape and the positive electrode active material layer can be set to match the measurement surface required by the device.

[0080] The characteristic X-rays may be monochromated using a filter or by using XRD data analysis software after obtaining an XRD pattern. For example, DEFFRAC.EVA (XRD data analysis software manufactured by Bruker) can be used to remove the peak due to CuKα2 radiation and extract only the peak due to CuKα1 radiation. The same software can also be used to remove background noise.

[0081] It is desirable to use the data that has undergone these preprocessing processes as an XRD profile.

[0082] <Operation Example of Material Search System> Next, an operation example of the material search system 100 will be described as an example of a material search method according to one embodiment of the present invention. Fig. 4 is a flowchart illustrating the operation example of the material search system 100.

[0083] First, it is determined whether to use an existing dataset 146 or a new dataset 146 as the dataset 146 to be used in step S317 and thereafter (step S311). If the material retrieval system 100 has multiple existing datasets 146, it is sufficient to determine which dataset 146 to use depending on the purpose, etc. If an existing dataset 146 is not to be used, a new dataset 146 is generated (step S312).

[0084] Next, an XRD profile 200 of the sample is acquired (step S313). The XRD profile 200 may be data input to the material retrieval system 100 via the input / output device 150 or the communication device 160, or may be data stored in the storage device 130 or the auxiliary storage device 140. The data format of the XRD profile 200 may be various, such as the out format, the int format, the csv format, or the dat format. FIG. 5A shows an example of the XRD profile 200. The input XRD profile 200 is stored in the storage device 130 or the auxiliary storage device 140.

[0085] Next, the calculation device 120 is used to identify the peak positions of the acquired XRD profile 200 (step S314). The peak positions may be identified using, for example, a differential method. If necessary, data that has been smoothed or the like may be used.

[0086] Next, the calculation device 120 calculates the peak intensities or their relative intensities at all peak positions. For example, the peak with the highest intensity is set as the reference (e.g., relative intensity 100.00), and the relative intensities of the other peaks are calculated (step S315). The calculated peak intensities or their relative intensities are stored in the storage device 130, auxiliary storage device 140, etc., together with the respective peak positions.

[0087] Next, P peak positions (P is an integer of 2 or more) are identified in descending order of peak intensity (or relative intensity) (step S316). In this embodiment, a case where P is 3 will be described. That is, the top three peaks with the highest peak intensities are identified from the XRD profile 200.

[0088] 5A shows a first peak 211, a second peak 212, and a third peak 213 identified in descending order of peak intensity. FIG. 5B shows the peak positions and relative values ​​of peak intensity of the first peak 211, the second peak 212, and the third peak 213.

[0089] The number P of peaks of a sample identified in descending order of peak intensity (or relative intensity) may be 2 to 10, preferably 2 to 5. As mentioned above, it is difficult to determine whether a material matches or roughly matches a single peak among multiple peaks appearing in an XRD profile. On the other hand, if the number P of peaks is too large, peaks with low relative intensity are easily confused with noise components, reducing detection accuracy.

[0090] Next, a record 145 having peaks that match all P peak positions is searched for from the dataset 146 (step S317, also referred to as "peak search"). Note that the search target may be the material database 141 instead of the dataset 146, but the detection accuracy may be reduced because the physical property data 142 contained in the material database 141 often contains information related to more than R peaks. By generating a dataset 146 having multiple records 145 in advance and using the dataset 146 as the search target, it is possible to efficiently search for materials in which all P peak positions match or approximately match. Note that if there is a record 145 with less than R peaks, 0 (zero) may be registered at the missing peak positions.

[0091] As described above, errors may occur in the intensity of the peaks of a sample due to the state of the sample, the state in which the sample is installed, etc., and the peak intensity order may be misidentified. For example, if the number R of peaks included in record 145 is equal to or less than the number P of peaks of the sample, there is a possibility that any of the P peaks of the sample may be present at or after the R+1th peak included in record 145. In this case, the correct record 145 will not be detected, and the search accuracy will decrease.

[0092] Therefore, R needs to be larger than P. That is, R needs to be P+1 or larger. On the other hand, if R is too large, peaks with low relative intensities are likely to be confused with noise components, resulting in a decrease in detection accuracy. The number of peaks R in one record 145 is preferably three times or less, and more preferably six times or less, the number of peaks P to be searched for.

[0093] In this embodiment, a case will be described where P is 3 and R is 7. In step S317, first, each of the multiple records 145 in the data set 146 is checked to see if it contains a peak that matches or approximately matches the peak position of the first peak 211.

[0094] At this time, if the relative difference E (absolute value of the difference) of the peak positions is within a certain range, it is determined that they match or approximately match. Specifically, if the relative difference E is 1.00° or less, preferably 0.50° or less, and more preferably 0.10° or less, it is determined that they match. Note that the relative difference E is a value greater than 0 (zero). In this specification and the like, the relative difference E may be referred to as the "detection range." Note that the relative difference E can be set arbitrarily by the user.

[0095] Next, among the records 145 having a peak whose peak position coincides or approximately coincides with that of the first peak 211, a record 145 having a peak whose peak position coincides or approximately coincides with that of the second peak 212 is searched for.

[0096] Next, among the records 145 having peaks that match or approximately match the peak positions of the first peak 211 and the second peak 212, a search is made for a record 145 having a peak that matches or approximately matches the peak position of the third peak 213.

[0097] 6 shows the peak positions of the first peak 211, the second peak 212, and the third peak 213 of the sample, and the LiCoO ２ 6 shows the record 145 of NCM811 and the record 145 of NCM812. Also, FIG. 6 shows the peak positions of the first peak 211, the second peak 212, and the third peak 213 of the sample, and the relative difference E between the seven peak positions included in the record 145.

[0098] From FIG. 6, LiCoO ２ It can be seen that the record 145 generated from the physical property data 142 of the sample contains peak positions whose relative difference E is 0.10° or less from the respective peak positions of the first peak 211, the second peak 212, and the third peak 213 of the sample. ２ It can be said that record 145 of has a peak that matches or approximately matches each of first peak 211, second peak 212, and third peak 213.

[0099] If a record 145 that matches or approximately matches the positions of the P peaks is found in the data set 146 (step S318), some or all of the physical property data 142 associated with the record 145, such as the material name, is output to the display device 170 or an external device (step S319). In this way, the material constituting the sample can be determined. According to one aspect of the present invention, a material search using an XRD profile can be realized without requiring advanced specialized knowledge.

[0100] [Modification of Peak Search] Peak search may be performed as follows. First, a range of the peak position of the first peak 211 ± the relative difference E (also referred to as the "first range") is set. Then, a range of the peak position of the second peak 212 ± the relative difference E (also referred to as the "second range") is set. Then, a range of the peak position of the third peak 213 ± the relative difference E (also referred to as the "third range") is set.

[0101] Next, all values ​​of Peak 1 (see FIG. 3 ) through Peak 7 contained in the data set 146 are compared with the first range (also referred to as the "first comparison process"), and a truth value of "true" is set for records 145 having peak positions included in the first range. Next, all values ​​of Peak 1 through Peak 7 contained in the data set 146 are compared with the second range (also referred to as the "second comparison process"), and a truth value of "true" is set for records 145 having peak positions included in the second range. Next, all values ​​of Peak 1 through Peak 7 contained in the data set 146 are compared with the third range (also referred to as the "third comparison process"), and a truth value of "true" is set for records 145 having peak positions included in the third range.

[0102] A record 145 for which true is set in all of the first comparison process, the second comparison process, and the third comparison process is determined to be a record 145 that matches or approximately matches the sample. The first comparison process, the second comparison process, and the third comparison process may be performed in sequence or simultaneously.

[0103] Note that AI (Artificial Intelligence) processing or machine learning may be used for the peak search. For example, a machine learning algorithm such as a decision tree may be used to identify materials.

[0104] 7 shows an example of the display screen of the display device 170. The display device 170 has a first display area 171, a second display area 172, and a third display area 173 on the display screen. The first display area 171 displays an XRD profile of the sample. The second display area 172 displays markers indicating peak positions calculated from the XRD profiles of materials determined to match or approximately match using the search method according to one aspect of the present invention.

[0105] While the first display area 171 and the second display area 172 are displayed vertically in FIG. 7 , they may be displayed horizontally, or the content displayed in the second display area 172 may be displayed in the first display area 171. For example, markers indicating peak positions of materials determined to match or approximately match the XRD profile of the material may be displayed overlaid on the XRD profile of the material. Furthermore, while the second display area 172 in FIG. 7 displays line markers perpendicular to the horizontal axis, the markers may be other than lines. When the markers are displayed as lines perpendicular to the horizontal axis, the length of the line may be associated with the relative intensity of the peak corresponding to the marker, or the line may be displayed as a constant length regardless of the relative intensity of the peak.

[0106] It is also preferable to match the horizontal axis (2θ) of the XRD profile displayed in the first display area 171 with the horizontal axis (2θ) of the second display area 172. This makes it easy to compare the XRD profile displayed in the first display area 171 with the markers displayed in the second display area 172.

[0107] Furthermore, the third display area 173 displays the names of materials that have been determined to match or approximately match the XRD profile of the sample. In this case, in addition to the material name, physical property values ​​contained in the physical property data 142, the management number in the material database 141, the management number of a related external database (e.g., ICSD collection code), etc. may also be displayed. Note that the information displayed on the display device 170 is not limited to the above. Various information can be displayed on the display device 170. For example, FIG. 7 shows the detection range (relative difference E) used in the peak search together with the material name.

[0108] Furthermore, the plane index for each peak position can be obtained from the physical property data 142 linked to the record 145 that has been determined to match or approximately match, and the lattice constant of the sample can be calculated using the plane index and the peak position obtained by measuring the sample. Furthermore, if the record 145 has information on the plane index for each peak position, the lattice constant of the sample can be calculated using the plane index included in the record 145 and the peak position obtained by measuring the sample. Specifically, the lattice constant of the sample can be calculated using Equation 1.

[0109] nλ=2d·sinθ (Formula 1)

[0110] In Equation 1, λ is the wavelength of the incident X-rays, d is the interplanar spacing, θ is the angle of incidence of the X-rays, and n is an integer. By using the interplanar spacing, appropriate plane indices, and information on the estimated crystal system of the material, it is possible to calculate the lattice constants of various crystal systems, such as cubic, hexagonal, or tetragonal. The calculated lattice constants may be output in the third display area 173 together with the name of the material, etc.

[0111] Furthermore, one embodiment of the present invention can be used not only for XRD analysis but also for a method in which an acquired profile is used for data analysis, such as Raman spectroscopy analysis, nuclear magnetic resonance (NMR) analysis, or X-ray photoelectron spectroscopy (XPS) analysis.

[0112] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0113] (Embodiment 2) In this embodiment, as an example of the operation of the material search system, a method of detecting (also referred to as "narrowing down") a record 145 having a peak position that most closely matches the peak position of the sample from among a plurality of detected records 145 will be described. Figures 8A and 8B are flowcharts for explaining the "narrowing down" method.

[0114] Note that there are cases where multiple material names are displayed in the third display area 173. As disclosed in the first embodiment, in the material search method according to one aspect of the present invention, the determination of whether the peak positions in the peak search match or approximately match is performed using the relative difference E (detection range) (steps S317 and S318). At this time, if the value of the relative difference E is large, two or more records 145 may be detected. If two or more records 145 are detected as a result of the peak search, the record 145 of the material that is closest to the sample can be found by performing the "narrowing down" disclosed in this embodiment.

[0115] The "narrowing down" can be achieved by repeating the resetting of the relative difference E and the peak search (also called a "narrowing down loop") until only one record 145 is detected. If the number of detected records 145 is two or more, the narrowing down loop is started (step S331).

[0116] In the narrowing-down loop, first, the relative difference E is reset (step S332). Specifically, the new relative difference E is determined by subtracting the adjustment value f from the relative difference E (see FIG. 8A). The adjustment value f may be set to a value greater than 0 (zero) and less than 1. The adjustment value f may be set to 0.001° or greater and 0.05° or less, and preferably 0.005° or greater and 0.02° or less. For example, the adjustment value f may be set to 0.01°.

[0117] Alternatively, the product of the relative difference E and the adjustment ratio fr may be used as the new relative difference E (see FIG. 8B ). When the product of the relative difference E and the adjustment ratio fr is used as the new relative difference E, the adjustment ratio fr may be set to 0.50 or greater and less than 1.00, and preferably 0.80 or greater and less than 1.00. By using the product of the relative difference E and the adjustment ratio fr as the new relative difference E, it is possible to prevent the new relative difference E from becoming a negative value.

[0118] Next, a peak search is performed using the reset relative difference E (step S333). In step S333, the peak search may be performed by searching the previously detected multiple records 145. Note that, similar to step S317 described in the first embodiment, all records 145 (data sets 146) may be used as search targets.

[0119] The narrowing loop is repeated until only one record 145 is detected. When only one record 145 is detected, the narrowing loop is terminated. In this way, the record 145 having the peak position that most closely matches the peak position of the sample can be detected. In other words, the record 145 of the material that is closest to the sample can be detected.

[0120] Thereafter, in the same manner as in step S319 described in the first embodiment, part or all of the physical property data 142 related to the record 145, such as the material name, is output to the display device 170 or an external device.

[0121] The "narrowing down" described in this embodiment may be performed automatically between step S318 and step S319 described in embodiment 1. Furthermore, the "narrowing down" may be performed as needed after executing the material search method described in embodiment 1. For example, the "narrowing down" may be performed by setting the relative difference E to 0.50° and the adjustment value f to 0.01°.

[0122] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0123] In this embodiment, as an example of the operation of the material search system, a method (also called "range expansion") for increasing the number of detected records 145 having peak positions that match those of a sample by expanding the detection range (relative difference E) will be described. Figures 9A and 9B are flowcharts for explaining "range expansion."

[0124] "Range expansion" can be achieved by repeatedly resetting the relative difference E and searching for peaks (also called a "range expansion loop"). First, the number of records 145 that have already been detected is stored as the number of detected records CD (step S351). If no records 145 have been detected, 0 (zero) is stored in the number of detected records CD. Next, the number of detected records CD is substituted for the number of detected records CN, making the number of detected records CN and the number of detected records CD the same (step S352).

[0125] If the number of detected records CN and the number of detected records CD are the same, a range expansion loop is started (step S353).

[0126] In the range expansion loop, first, the relative difference E is reset (step S354). Specifically, the relative difference E is added to the adjustment value f to obtain the new relative difference E (see FIG. 9A). The adjustment value f may be set to a value greater than 0 (zero) and less than 1. The adjustment value f may be set to 0.001° or greater and 0.05° or less, and preferably 0.005° or greater and 0.02° or less. For example, the adjustment value f may be set to 0.01°.

[0127] Alternatively, the value obtained by dividing the relative difference E by the adjustment ratio fr may be used as the new relative difference E (see FIG. 9B ). When the value obtained by dividing the relative difference E by the adjustment ratio fr is used as the new relative difference E, the adjustment ratio fr may be set to 0.70 or greater and less than 1.00, preferably 0.80 or greater and less than 1.00.

[0128] Next, a peak search is performed using the reset relative difference E (step S355). In step S355, a peak search is performed using the data set 146 as the search target. The number of records 145 detected in step S355 is stored as the number of detected records CN.

[0129] The range expansion loop is repeated until the number of detected records CN becomes greater than the number of detected records CD. When the number of detected records CN becomes greater than the number of detected records CD, the range expansion loop is terminated. In this way, the number of detected records 145 having peak positions that match the peak positions of the sample can be increased.

[0130] "Expand range" is suitable when the number of detected records CD is 0 (zero) or when it is desired to increase the number of candidate materials that match the sample.

[0131] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0132] (Embodiment 4) A material retrieval system 100 according to an aspect of the present invention has a function (also called "peak filtering") of extracting from the material database 141 materials whose physical property data 142 includes a specific peak position and its neighboring peak positions, and presenting them to a user.

[0133] Peak filtering can be used to easily identify impurity materials contained in a sample, and to identify each material in a sample composed of multiple materials. In this embodiment, the identification of impurity materials using peak filtering will be described. In this specification, the term "impurity material" refers to a material different from the main component material, a material unintentionally mixed in during sample synthesis, or a material unintentionally generated during sample synthesis.

[0134] Fig. 10A shows an example of the display screen of display device 170. Display device 170 shown in Fig. 10A has first display area 171, second display area 172, third display area 173, and fourth display area 174 on the display screen.

[0135] 10A , an XRD profile 200a having peak positions (2θ) ranging from 36.00° to 39.70° is shown in a first display area 171. A first peak 211a, a second peak 212a, a third peak 213a, and a fourth peak 214a are confirmed in the XRD profile 200a in FIG. Furthermore, a second display area 172 displays markers (markers 221, 222, and 223) indicating the peak positions of materials determined to match or approximately match using the search method disclosed in the first embodiment, and a third display area 173 displays the names of the materials.

[0136] The fourth display area 174 displays a filter condition 181 used when performing peak filtering, and a data set 182 extracted from the material database 141 in accordance with the filter condition 181 .

[0137] 10B shows an example of the filter condition 181. In FIG. 10B, the filter condition 181 shows a range 181a of peak positions indicated by 2θ and a relative intensity 181b. The relative intensity 181b is a peak intensity normalized by the maximum peak intensity of the XRD profile 200a. In the peak filtering, materials having peaks included in the range 181a and having relative intensities equal to or greater than the relative intensity 181b are extracted from the material database 141, and a set of records 183 including the extracted material names, the positions of the corresponding peaks, and the relative intensities of the peaks is displayed as a data set 182 (see FIG. 10C).

[0138] Note that "the relative intensity of the peak is 181b or more" means that, for example, when the maximum value of the relative intensity is 100, the relative intensity of the peak is in the range of 181b or more and 100 or less.

[0139] For example, in the XRD profile 200a shown in FIG. 10A, LiCoO ２ In addition to the first peak 211a, second peak 212a, and third peak 213a, which coincide with the peaks of (1), a fourth peak 214a is present at a position of 36.88°. In such a case, it is highly likely that the sample contains an impurity material. Peak filtering can be used to determine what material the fourth peak 214a is derived from.

[0140] The determination of the material by peak filtering may be performed as follows: First, a range 181a is set. In this embodiment, since the peak position of the fourth peak 214a is 36.88°, the range 181a is set to, for example, 36.50° or more and 37.50° or less.

[0141] Next, the relative intensity 181b is set. In FIG. 10B , the relative intensity 181b is set to 0 (zero) or greater. The range 181a and the relative intensity 181b can be set by various means. For example, a set value may be input into a text box set on the screen using a touch panel, mouse, keyboard, or the like superimposed on the display screen of the display device 170. Alternatively, a method may be used in which a slide bar set on the screen is operated using a mouse or touch panel, and the set value is determined according to the state of the slide bar. The operation of operating the slide bar and determining the set value according to the state of the slide bar can be realized, for example, by Javascript. The range 181a may also be automatically set based on the peak position of the peak to be filtered. The slide bar may also be referred to as a slider or slider bar.

[0142] FIG. 10C shows an example of a data set 182 generated from the material database 141 in accordance with the above-described filter condition 181. Looking at the data set 182 shown in FIG. 10C , it can be seen that there are multiple materials having peaks that match the filter condition 181. Among these, peaks with extremely low relative intensities are difficult to distinguish from noise components in the XRD profile. If the data set 182 includes peaks with extremely low relative intensities, accurate determination takes time, reducing the efficiency of the determination. Furthermore, since information about peaks that are difficult to distinguish from noise components contributes to a decrease in the accuracy of the determination, it is preferable to exclude such peaks from the data set 182.

[0143] The removal of materials with peaks having extremely small relative intensities extracted under the filter condition 181 can be achieved by increasing the relative intensity 181b of the filter condition 181. For example, by increasing the relative intensity 181b (see FIG. 11A), a data set 182 is obtained in which materials with peaks having extremely small relative intensities are removed (see FIG. 11B). Note that the set value of the relative intensity 181b for removing noise components from the data set 182 is preferably 5 or more and 15 or less. On the other hand, if the material has a crystalline structure with 10 or more peaks in the measurement range (for example, Li ２ CO ３In cases where the relative intensity 181b for removing noise components is large, the set value may be set to 30 or less or 60 or less. The set value of the relative intensity 181b for removing noise components may be set appropriately as needed.

[0144] From the data set 182 shown in FIG. ３ O ４ It can be seen that the peak at 36.90° of Co is closest to the fourth peak 214a and has a relative intensity exceeding the relative intensity 181b. ３ O ４ It can be determined that the peak is highly likely to be derived from Co. ３ O ４ It can be determined that there is a high possibility that

[0145] It is also preferable to display the peak of the material contained in the data set 182 superimposed on the XRD profile 200a displayed in the first display area 171. For example, a peak of any material may be selected from the data set 182, and a line may be displayed at a position on the XRD profile 200a that coincides with the selected peak.

[0146] 11C is a diagram showing a display example of the first display area 171 and the second display area 172. In FIG. 11C, in the first display area 171, ３ O ４ A marker 224 indicating the position of the peak position of 36.90° derived from the XRD profile 200a is shown superimposed on the XRD profile 200a. The marker 224 may be shown in the second display area 172, or may be shown in both the first display area 171 and the second display area 172.

[0147] 11C , the markers 224 shown in the first display area 171 are represented by dashed lines perpendicular to the horizontal axis, and the markers 224 shown in the second display area 172 are represented by straight lines perpendicular to the horizontal axis. Note that the markers indicating the peak positions may be something other than lines. When the markers are represented by lines, the length of the lines may be related to the relative intensity of the peaks corresponding to the markers, or the lines may be displayed at a constant length regardless of the relative intensity of the peaks.

[0148] By arbitrarily or sequentially selecting materials from the dataset 182 displayed on the display screen and displaying markers indicating the peak positions of the materials superimposed on the XRD profile 200a, the peak closest to the fourth peak 214a can be visually grasped.

[0149] Furthermore, the number of ranges 181a set in the filter condition 181 is not limited to one. FIG. 12A shows an example in which two peak ranges, range 181a1 and range 181a2, are set in the filter condition 181. By setting two ranges 181a, it is possible to extract from the material database 141 both materials having peaks included in range 181a1 and materials having peaks included in range 181a2. This makes it possible to efficiently identify the materials from which each of the multiple peaks originates. Note that three or more ranges 181a may be set in the filter condition 181.

[0150] Furthermore, the conditions set in the filter condition 181 are not limited to the range 181a and the relative intensity 181b. For example, a material name containing character 181c may be set in the filter condition 181 (FIG. 12B). Also, for example, a plane index 181d may be set in the filter condition 181 (FIG. 12C). Various conditions other than those described above may be set as the conditions set in the filter condition 181.

[0151] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0152] 100: material search system, 110: control device, 120: computing device, 130: storage device, 140: auxiliary storage device, 141: material database, 142: physical property data, 145: record, 146: data set, 150: input / output device, 160: communication device, 170: display device, 171: first display area, 172: second display area, 173: third display area, 200: XRD profile, 211: first peak, 212: second peak, 213: third peak, 510: server, 520: cloud system

Claims

1. A material search method using XRD profiles and a first dataset, The first dataset is, The system has multiple records containing R first peak positions extracted from the physical property data of multiple known materials, in descending order of peak intensity for each of the physical property data. From the XRD profile of the first material, the positions and intensities of multiple second peaks were identified. From the plurality of second peak positions and intensities mentioned above, P second peak positions are obtained in descending order of peak intensity. In the first dataset, The record containing the R first peak positions that match or roughly match each of the P second peak positions is searched. If there is a record that matches or closely matches, and the relative difference E between the second peak position of each of the P records and the first peak positions of the R records is greater than 0 and less than or equal to 0.10°, then it is determined that the known material related to the matching record and the first material are the same. The P values ​​of P are integers between 2 and 10, A material search method in which the R values ​​of R are integers greater than the P values.

2. In claim 1, A method for finding a material in which R is 6 times or less than P.

3. In claim 1, The record has R surface indices corresponding to each of the R first peak positions, Using the first peak position and the surface index, A material search method for calculating the lattice constant of the first material which has been determined to be the same as the known material.

4. The material search method according to claims 1 to 3, A program designed to run on a computer.

5. A computer-readable recording medium on which the program described in claim 4 is recorded.

6. The program described in claim 4, written in HTML.

7. A material search system using XRD profiles and a first dataset, The first dataset is, The system has multiple records containing R first peak positions extracted from the physical property data of multiple known materials, in descending order of peak intensity for each of the physical property data. The function identifies the positions and intensities of multiple second peaks from the XRD profile of the first material, A function to acquire P of the aforementioned second peak positions in descending order of peak intensity from among the plurality of second peak positions and intensities, In the first dataset, A function to search for records that include R first peak positions that match or roughly match each of the P second peak positions, If there is a record that matches or closely matches the previous record, and the relative difference E between the second peak position of each of the P records and the first peak positions of the R records is greater than 0 and less than or equal to 0.10°, then the system has a function to determine that the known material related to the matched record and the first material are the same. The P values ​​of P are integers between 2 and 10, A material search system in which the R values ​​of R are integers greater than the P values.

8. In claim 7, A material search system in which R is 6 times or less than P.

9. In claim 7, The record has R surface indices corresponding to each of the R first peak positions, Using the first peak position and the surface index, A material search system having a function to calculate the lattice constant of the first material which has been determined to be the same as the known material.

10. The material search system according to claims 7 to 9, A program designed to be implemented using a computer.

11. A computer-readable recording medium on which the program described in claim 10 is recorded.

12. The program described in claim 10, written in HTML.