X-ray analysis device, x-ray analysis method, information processing device, and computer program

Abstract

Provided are: an X-ray analysis device that is capable of individually measuring the amounts of elements contained in layers on the obverse surface side and the reverse surface side of a multilayer sample; an X-ray analysis method; an information processing device; and a computer program.　This X-ray analysis device is provided with: an emission unit that emits X-rays to a sample in which a plurality of layers are laminated, so as to sequentially penetrate a first layer, an intermediate layer, and a second layer; a fluorescent X-ray detector that detects fluorescent X-rays generated from the first layer or the second layer; a penetrating X-ray detector that detects penetrating X-rays that have penetrated the sample; and an analysis unit. The analysis unit calculates the amount of a specific element contained in one of the first layer or the second layer in accordance with the intensity of fluorescent X-rays having a prescribed first energy, calculates the total amount of the specific element contained in the first layer and the second layer in accordance with the intensity of penetrating X-rays having a prescribed second energy higher than the first energy, and calculates the amount of the specific element contained in the other of the first layer or the second layer.

Description

X-ray analysis device, X-ray analysis method, information processing device, and computer program

[0001] The present invention relates to an X-ray analysis apparatus, an X-ray analysis method, an information processing apparatus, and a computer program.

[0002] It is sometimes desirable to analyze layers on the front and back sides of a multilayer sample. For example, a fuel cell includes a multilayer membrane in which catalyst layers are bonded to both sides of an electrolyte layer made of a polymer membrane, and it is sometimes desirable to measure the amount of a specific element contained in each catalyst layer. One method for analyzing a multilayer sample involves irradiating the multilayer sample with X-rays, detecting fluorescent X-rays emitted from each layer, and performing analysis based on the fluorescent X-rays. Another method involves detecting transmitted X-rays that have passed through the multilayer sample and performing analysis based on the transmitted X-rays. Patent Document 1 discloses a technique for measuring the thickness of a sample based on transmitted X-rays.

[0003] Japanese Patent Application Publication No. 11-287643

[0004] In methods that use fluorescent X-rays, fluorescent X-rays emitted from both a front layer and a back layer may be detected at the same time, and the influence of the fluorescent X-rays from both layers must be taken into consideration. Since information about transmitted X-rays is a superposition of information about multiple layers, the influence of multiple layers must also be taken into consideration in methods that use transmitted X-rays. For this reason, it is not easy to separately measure the amounts of elements contained in the front layer and the back layer of a multilayer sample.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an X-ray analysis apparatus, an X-ray analysis method, an information processing apparatus, and a computer program that can individually measure the amounts of elements contained in a layer on the front side and a layer on the back side of a multilayer sample.

[0006] An X-ray analysis apparatus according to one aspect of the present invention includes an irradiation unit that irradiates a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first and second layers, with X-rays so that the X-rays pass through the first layer, the intermediate layer, and the second layer in that order; an X-ray fluorescence detector that detects fluorescent X-rays generated from the first layer or the second layer; a transmission X-ray detector that detects transmitted X-rays that have passed through the sample; and an analysis unit, wherein the analysis unit calculates an amount of a specific element contained in one of the first layer or the second layer in accordance with the intensity of the fluorescent X-rays having a predetermined first energy that are contained in the fluorescent X-rays detected by the X-ray fluorescence detector; calculates a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with the intensity of the transmitted X-rays having a predetermined second energy that is higher than the first energy that are contained in the transmitted X-rays detected by the transmission X-ray detector; and calculates the amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

[0007] In one aspect of the present invention, an X-ray analysis apparatus irradiates a sample including a first layer, an intermediate layer, and a second layer with X-rays, detects fluorescent X-rays generated from the first layer, and detects transmitted X-rays that have passed through the sample. Since the X-rays are irradiated so as to pass through the first layer, the intermediate layer, and the second layer in that order, the first layer is located on the front side of the sample, and the second layer is located on the back side of the sample. The analysis unit calculates the amount of a specific element contained in either the first layer or the second layer based on the intensity of the fluorescent X-rays having a first energy. The analysis unit calculates the sum of the amounts of the specific element contained in the first layer and the second layer based on the amount of the specific element contained in either the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer. In this manner, the X-ray analysis apparatus measures the amount of the specific element contained in each of the first layer and the second layer.

[0008] In one aspect of the X-ray analysis apparatus of the present invention, the first energy is the energy of fluorescent X-rays derived from a specific electron shell, and the second energy is the energy of an absorption edge derived from an electron shell one outer shell of the specific electron shell.

[0009] In one embodiment of the present invention, the first energy is the energy of fluorescent X-rays generated when electrons in a specific electron shell are excited and transition to the ground state. The second energy is the energy at which X-rays are absorbed by exciting electrons in the electron shell one outermost. Therefore, the second energy is higher than the first energy.

[0010] In one embodiment of the X-ray analysis apparatus of the present invention, the irradiation unit has an X-ray generation unit that generates X-rays by colliding accelerated electrons with a target, and the X-ray generation unit determines the magnitude of the voltage for accelerating the electrons so that the maximum energy of the generated X-rays becomes a predetermined third energy that is higher than the second energy.

[0011] In one aspect of the present invention, an X-ray analysis apparatus irradiates a sample with X-rays generated by colliding accelerated electrons with a target. The X-ray analysis apparatus determines the magnitude of a voltage for accelerating the electrons so that the maximum energy value of the generated X-rays becomes a predetermined third energy that is higher than the energy of the transmitted X-rays used to calculate the amount of a specific element. By setting the third energy to an appropriate value, the intensity of the transmitted X-rays used to calculate the amount of the specific element can be accurately obtained, and the amount of the specific element can be accurately measured.

[0012] In the X-ray analysis apparatus according to one aspect of the present invention, the third energy is higher than the second energy by 1 to 3 keV.

[0013] In one embodiment of the present invention, the X-ray analysis apparatus sets the third energy to be higher than the second energy by 1 to 3 keV, thereby obtaining transmitted X-rays used to calculate the amount of a specific element, and the X-ray analysis apparatus can measure the amount of platinum contained in each of the first layer and the second layer.

[0014] In an X-ray analysis apparatus according to one aspect of the present invention, the specific element is platinum or iridium, and the analysis unit calculates the amount of platinum or iridium contained in one of the first layer or the second layer according to the intensity of an M-ray of platinum or iridium contained in the fluorescent X-rays detected by the X-ray fluorescence detector, and calculates the total amount of platinum or iridium contained in the first layer and the second layer according to the intensity of an L-absorption edge of platinum or iridium contained in the transmitted X-rays detected by the transmitted X-ray detector.

[0015] In one embodiment of the present invention, the specific element is platinum or iridium, and the analysis unit calculates the amount of platinum or iridium contained in one of the first layer or the second layer according to the intensity of the M-ray of platinum or iridium contained in the fluorescent X-ray. The analysis unit also calculates the total amount of platinum or iridium contained in the first and second layers according to the intensity of the L-absorption edge of platinum or iridium contained in the transmitted X-ray. In this way, the X-ray analysis device measures the amount of platinum or iridium contained in each of the first and second layers.

[0016] In an X-ray analysis apparatus according to one aspect of the present invention, the specific element is ruthenium, rhodium, or palladium, and the analysis unit calculates the amount of ruthenium, rhodium, or palladium contained in one of the first layer or the second layer according to the intensity of the L-line of ruthenium, rhodium, or palladium contained in the fluorescent X-rays detected by the X-ray fluorescence detector, and calculates the total amount of ruthenium, rhodium, or palladium contained in the first layer and the second layer according to the intensity of the K-absorption edge of ruthenium, rhodium, or palladium contained in the transmitted X-rays detected by the transmitted X-ray detector.

[0017] In one embodiment of the present invention, the specific element is ruthenium, rhodium, or palladium, and the analysis unit calculates the amount of ruthenium, rhodium, or palladium contained in one of the first layer or the second layer according to the intensity of the L-line of ruthenium, rhodium, or palladium contained in the fluorescent X-rays. The analysis unit also calculates the total amount of ruthenium, rhodium, or palladium contained in the first and second layers according to the intensity of the K-absorption edge of ruthenium, rhodium, or palladium contained in the transmitted X-rays. In this manner, the X-ray analysis device measures the amount of ruthenium, rhodium, or palladium contained in each of the first and second layers.

[0018] An X-ray analysis method according to one aspect of the present invention includes the steps of: irradiating a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first and second layers, with X-rays so that the X-rays pass through the first layer, the intermediate layer, and the second layer in that order; detecting fluorescent X-rays emitted from the first layer or the second layer; detecting transmitted X-rays that have passed through the sample; calculating an amount of a specific element contained in one of the first layer or the second layer in accordance with an intensity of the fluorescent X-rays having a predetermined first energy that are contained in the detected fluorescent X-rays; calculating a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with an intensity of transmitted X-rays having a predetermined second energy that is higher than the first energy that are contained in the detected transmitted X-rays; and calculating the amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

[0019] In one aspect of the present invention, a sample including a first layer, an intermediate layer, and a second layer is irradiated with X-rays, fluorescent X-rays generated from the first layer are detected, and transmitted X-rays transmitted through the sample are detected. The amount of a specific element contained in one of the first layer or the second layer is calculated based on the intensity of the fluorescent X-rays having a first energy. The sum of the amounts of the specific element contained in the first layer and the second layer is calculated based on the intensity of the transmitted X-rays having a second energy higher than the first energy. Next, the amount of the specific element contained in the other of the first layer or the second layer is calculated. In this manner, the amounts of the specific element contained in each of the first layer and the second layer are measured.

[0020] In an X-ray analysis method according to one aspect of the present invention, the intermediate layer is a polymer film, and the first layer and the second layer are catalyst layers containing platinum, iridium, ruthenium, rhodium, or palladium.

[0021] In one embodiment of the present invention, the intermediate layer is a polymer membrane, and the first and second layers are catalyst layers containing platinum, iridium, ruthenium, rhodium, or palladium. For example, the sample may be incorporated into a fuel cell, with the intermediate layer functioning as an electrolyte membrane and the first and second layers functioning as catalyst layers. Based on the measured amount of platinum, iridium, ruthenium, rhodium, or palladium, the performance of the fuel cell may be predicted.

[0022] An information processing device according to one aspect of the present invention includes a calculation unit that irradiates a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first and second layers, with X-rays passing through the first layer, the intermediate layer, and the second layer in that order, obtains a result of detecting fluorescent X-rays generated from the first layer or the second layer and a result of detecting transmitted X-rays that have passed through the sample, calculates an amount of a specific element contained in one of the first layer or the second layer in accordance with an intensity of the fluorescent X-rays that are contained in the detected fluorescent X-rays and have a predetermined first energy, calculates a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with an intensity of transmitted X-rays that are contained in the detected transmitted X-rays and have a predetermined second energy that is higher than the first energy, and calculates the amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

[0023] A computer program according to one aspect of the present invention causes a computer to perform the following processes: irradiating a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first and second layers, with X-rays so as to pass through the first layer, the intermediate layer, and the second layer in that order; calculating, based on a result of detecting fluorescent X-rays generated from the first layer or the second layer, an amount of a specific element contained in one of the first layer or the second layer in accordance with an intensity of the fluorescent X-rays that are contained in the detected fluorescent X-rays and have a predetermined first energy; calculating, based on a result of detecting transmitted X-rays that have transmitted through the sample, a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with an intensity of transmitted X-rays that are contained in the detected transmitted X-rays and have a predetermined second energy that is higher than the first energy; and calculating the amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

[0024] In one aspect of the present invention, a sample including a first layer, an intermediate layer, and a second layer is irradiated with X-rays, and the amount of a specific element contained in one of the first layer or the second layer is calculated according to the intensity of fluorescent X-rays having a first energy. The sum of the amounts of the specific element contained in the first layer and the second layer is calculated according to the intensity of transmitted X-rays having a second energy higher than the first energy, and then the amount of the specific element contained in the other of the first layer or the second layer is calculated. In this way, the amount of the specific element contained in each of the first layer and the second layer is measured.

[0025] The present invention has excellent effects, such as making it possible to measure the amounts of specific elements contained in the layers on the front side and the back side of a multilayer sample individually.

[0026] FIG. 6 is a block diagram showing an example of the functional configuration of an X-ray analysis device. FIG. 7 is a block diagram showing an example of the internal configuration of an analysis unit. FIG. 8 is a schematic cross-sectional view of a sample. FIG. 9 is a graph showing an example of a spectrum of fluorescent X-rays. FIG. 10 is a graph showing an example of a spectrum of transmitted X-rays. FIG. 11 is a flowchart showing an example of a procedure of a process executed by an X-ray analysis device. FIG. 12 is a schematic diagram showing an example of the configuration of an irradiation unit. FIG. 13 is a graph showing an example of a spectrum of transmitted X-rays obtained when the voltage applied by the voltage application unit is different from that in FIG. 5. FIG. 14 is a block diagram showing an example of the functional configuration of an X-ray analysis device according to another embodiment.

[0027] The present invention will be described in detail below with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram showing an example of the functional configuration of an X-ray analysis apparatus 100. The X-ray analysis apparatus 100 includes an irradiation unit 3 that irradiates a sample 4 with X-rays, an X-ray fluorescence detector 22 that detects fluorescent X-rays generated from the sample 4 irradiated with X-rays, and a transmission X-ray detector 23 that detects transmitted X-rays that have passed through the sample 4. The sample 4 is a multilayer sample including multiple stacked layers, and includes at least three layers. The X-ray analysis apparatus 100 performs an X-ray analysis method to measure the amount of a specific element contained in a first layer on the front side of the sample 4 and a second layer on the back side of the sample 4. The irradiation unit 3 includes an X-ray generation unit that generates X-rays. The X-ray generation unit will be described later. In FIG. 1, arrows indicate the X-rays, fluorescent X-rays, and transmitted X-rays irradiated to the sample 4.

[0028] The X-ray fluorescence detector 22 and the transmission X-ray detector 23 are radiation detectors having radiation detection elements made of semiconductors. For example, the X-ray fluorescence detector 22 and the transmission X-ray detector 23 are silicon drift detectors (SDDs). The X-ray fluorescence detector 22 is disposed so as to face the surface of the sample 4 that is irradiated with X-rays. When X-rays are irradiated onto the sample 4 from the irradiation unit 3, fluorescent X-rays are generated in the sample 4. The fluorescent X-rays are emitted from the surface of the sample 4 and enter the X-ray fluorescence detector 22. The X-ray fluorescence detector 22 detects the incident fluorescent X-rays and outputs a signal with an intensity corresponding to the energy of the fluorescent X-rays.

[0029] The transmission X-ray detector 23 is disposed at a position facing the irradiation unit 3. With the sample 4 disposed between the irradiation unit 3 and the transmission X-ray detector 23, X-rays are irradiated from the irradiation unit 3 to the sample 4. A portion of the X-rays irradiated from the irradiation unit 3 to the sample 4 are transmitted through the sample 4. The X-rays that have transmitted through the sample 4 are called transmitted X-rays. The transmitted X-rays are incident on the transmission X-ray detector 23. The transmission X-ray detector 23 detects the incident transmitted X-rays and outputs a signal with an intensity corresponding to the energy of the transmitted X-rays.

[0030] A first signal processing unit 24 is connected to the fluorescent X-ray detector 22, and a second signal processing unit 25 is connected to the transmission X-ray detector 23. The first signal processing unit 24 and the second signal processing unit 25 are connected to the analysis unit 1. The analysis unit 1 is configured using a computer. A display unit 26 such as a liquid crystal display or an EL display (Electroluminescent Display) is connected to the analysis unit 1. The irradiation unit 3, the first signal processing unit 24, the second signal processing unit 25, and the analysis unit 1 are connected to the control unit 21.

[0031] The control unit 21 controls the operations of the irradiation unit 3, the first signal processing unit 24, the second signal processing unit 25, and the analysis unit 1. The control unit 21 is configured using a computer including a calculation unit that executes calculations to control each unit. The control unit 21 may be configured to receive operations from a user and control each unit of the X-ray analysis apparatus 100 in accordance with the received operations.

[0032] The X-ray fluorescence detector 22 outputs a signal having an intensity corresponding to the energy of the detected fluorescent X-rays, and the first signal processing unit 24 receives the signal output by the X-ray fluorescence detector 22. The first signal processing unit 24 detects the intensity of the received signal, thereby detecting a signal value corresponding to the energy of the fluorescent X-rays detected by the X-ray fluorescence detector 22. The first signal processing unit 24 counts the signals for each signal value, and outputs data indicating the relationship between the signal value and the count number to the analysis unit 1.

[0033] The transmission X-ray detector 23 outputs a signal having an intensity corresponding to the energy of the detected transmission X-ray, and the second signal processing unit 25 receives the signal output by the transmission X-ray detector 23. The second signal processing unit 25 detects the intensity of the received signal, thereby detecting a signal value corresponding to the energy of the transmission X-ray detected by the transmission X-ray detector 23. The second signal processing unit 25 counts the signals for each signal value, and outputs data indicating the relationship between the signal value and the count number to the analysis unit 1.

[0034] The analysis unit 1 receives data indicating the relationship between the signal value and the count number output by the first signal processing unit 24. The analysis unit 1 generates a spectrum of the fluorescent X-rays detected by the fluorescent X-ray detector 22 based on the data from the first signal processing unit 24. The signal value corresponds to the energy of the fluorescent X-rays, and the count number corresponds to the number of times the fluorescent X-rays are detected, i.e., the intensity of the fluorescent X-rays. Therefore, a spectrum of the fluorescent X-rays indicating the relationship between the energy and intensity of the fluorescent X-rays can be obtained from the relationship between the signal value and the count number.

[0035] The analysis unit 1 also receives data indicating the relationship between the signal value and the count number output by the second signal processing unit 25. The analysis unit 1 generates a spectrum of the transmitted X-rays detected by the transmitted X-ray detector 23 based on the data from the second signal processing unit 25. The signal value corresponds to the energy of the transmitted X-rays, and the count number corresponds to the number of times the transmitted X-rays are detected, i.e., the intensity of the transmitted X-rays. Therefore, the spectrum of the transmitted X-rays indicating the relationship between the energy and intensity of the transmitted X-rays can be obtained from the relationship between the signal value and the count number.

[0036] The process of counting the signals output by the X-ray fluorescence detector 22 and the X-ray transmission detector 23 by signal value may be performed by the analysis unit 1, rather than by the first signal processing unit 24 and the second signal processing unit 25. The generation of the fluorescent X-ray spectrum may be performed by the first signal processing unit 24, and the generation of the transmitted X-ray spectrum may be performed by the second signal processing unit 25. The analysis unit 1 stores spectral data representing the fluorescent X-ray spectrum and spectral data representing the transmitted X-ray spectrum. The display unit 26 displays the spectrum of the fluorescent X-ray or the transmitted X-ray. The user can check the spectrum of the fluorescent X-ray from the sample 4 or the spectrum of the transmitted X-ray that has passed through the sample 4. The analysis unit 1 also performs information processing based on the spectra of the fluorescent X-ray and the transmitted X-ray. More specifically, the analysis unit 1 performs information processing to measure the amount of a specific element contained in the first layer and the second layer of the sample 4. The analysis unit 1 corresponds to an information processing device that performs information processing to measure the amount of a specific element.

[0037] FIG. 2 is a block diagram showing an example of the internal configuration of the analysis unit 1. The analysis unit 1 is configured using a computer such as a personal computer. The analysis unit 1 includes a calculation unit 11, a memory 12, a reading unit 13, a storage unit 14, and an operation unit 15. The calculation unit 11 is configured using, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a multi-core CPU. The calculation unit 11 may also be configured using a quantum computer. The memory 12 stores temporary data generated in conjunction with calculations. The memory 12 is, for example, a RAM (Random Access Memory).

[0038] The reading unit 13 reads information from the recording medium 10, such as an optical disk or portable memory. The storage unit 14 is non-volatile, for example, a hard disk or non-volatile semiconductor memory. The operation unit 15 receives input of information such as text by receiving operations from the user. The operation unit 15 is, for example, a touch panel, keyboard, or pointing device. The user operates the operation unit 15 to input various instructions to the analysis unit 1. The analysis unit 1 receives the instructions input using the operation unit 15.

[0039] The calculation unit 11 causes the reading unit 13 to read the computer program 141 recorded on the recording medium 10, and stores the read computer program 141 in the storage unit 14. The calculation unit 11 executes processing required for the analysis unit 1 in accordance with the computer program 141. Alternatively, the computer program 141 may be stored in the storage unit 14 in advance, or may be downloaded from outside the analysis unit 1. In this case, the analysis unit 1 does not need to be equipped with the reading unit 13. The computer program 141 may be a program product.

[0040] The computer program 141 can be deployed to run on a single computer, or on multiple computers located at one site or distributed across multiple sites and interconnected by a communications network. That is, the computer program 141 may be executed on multiple computers connected via a communications network, and the analysis unit 1 may be configured using a cloud server.

[0041] The analysis unit 1 is connected to the display unit 26, the first signal processing unit 24, the second signal processing unit 25, and the control unit 21. The display unit 26 displays an image. The analysis unit 1 outputs information necessary for information processing by displaying an image including information on the display unit 26. The analysis unit 1 accepts signals from the first signal processing unit 24 and the second signal processing unit 25, and accepts control signals from the control unit 21. The analysis unit 1 and the control unit 21 may be configured as the same computer.

[0042] The memory unit 14 stores standard data recording the results of X-ray analysis using a standard sample. For example, the standard data includes the spectra of fluorescent X-rays and transmitted X-rays obtained from the standard sample. For example, the standard sample is a sample containing a specific element uniformly at a specific concentration. For example, the standard data includes information indicating the position of a peak due to a specific element in the fluorescent X-ray spectrum and information indicating the position of an absorption edge of a specific element in the transmitted X-ray spectrum. The peak position and the absorption edge position are expressed in terms of X-ray energy. For example, the standard data includes the relationship between the amount of a specific element contained in the standard sample and the intensity of the peak due to the specific element and the intensity of the absorption edge of the specific element. The standard data may be stored in a memory device external to the analysis unit 1.

[0043] FIG. 3 is a schematic cross-sectional view of sample 4. Sample 4 is flat. Sample 4 is positioned so that X-rays from the irradiation unit 3 irradiate one side of the sample 4. In FIG. 3, X-rays are indicated by arrows, and X-rays irradiated from the irradiation unit 3 to sample 4 are referred to as irradiated X-rays. The surface irradiated with X-rays from the irradiation unit 3 is referred to as the front surface of sample 4, and the surface behind the front surface is referred to as the back surface of sample 4. Sample 4 includes a first layer 41 including the front surface, a second layer 42 including the back surface, and an intermediate layer 43 located between the first layer 41 and the second layer 42. The first layer 41, the second layer 42, and the intermediate layer 43 are stacked. The intermediate layer 43 may be composed of multiple stacked layers. Note that the first layer 41 does not necessarily have to include the front surface, as long as it is closer to the front surface than the intermediate layer 43. Similarly, the second layer 42 does not necessarily have to include the back surface, as long as it is closer to the back surface than the intermediate layer 43. For example, the first layer 41 or the second layer 42 may be coated.

[0044] In this embodiment, the intermediate layer 43 is a polymer membrane, and the first layer 41 and the second layer 42 are catalyst layers containing platinum. The sample 4 is incorporated into a fuel cell, where the intermediate layer 43 functions as an electrolyte membrane, and the platinum contained in the first layer 41 and the second layer 42 can function as a catalyst. For example, the sample 4 has a rectangular shape with sides measuring several tens of centimeters in a plan view, and the first layer 41, the second layer 42, and the intermediate layer 43 each have a thickness of several hundreds of μm. The platinum contained in the first layer 41 and the second layer 42 corresponds to a specific element. The X-ray analysis apparatus 100 performs processing to measure the amount of platinum contained in the first layer 41 and the second layer 42.

[0045] 3, X-rays are irradiated onto the sample 4 so that the X-rays pass through the first layer 41, the intermediate layer 43, and the second layer 42 in this order. Fluorescent X-rays are generated from the first layer 41 irradiated with the X-rays. The fluorescent X-rays detected by the X-ray fluorescence detector 22 are mainly fluorescent X-rays generated from the first layer 41. The fluorescent X-rays generated from the second layer 42 are absorbed by the intermediate layer 43 and the first layer 41 and are attenuated.

[0046] The first energy is defined as the energy of fluorescent X-rays originating from a specific electron shell of a specific element. Fluorescent X-rays originating from a specific electron shell are fluorescent X-rays generated when electrons contained in the specific electron shell are excited and the excited electrons transition to the ground state. Furthermore, it is assumed that X-rays having the first energy do not pass through the intermediate layer 43. The second energy is defined as the energy of an absorption edge originating from an electron shell one shell outer than the specific electron shell. The second energy is the energy at which rapid X-ray absorption occurs due to excitation of electrons contained in an electron shell one shell outer than the specific electron shell. The second energy is higher than the first energy. It is also assumed that X-rays having the second energy pass through the intermediate layer 43.

[0047] FIG. 4 is a graph showing an example of a fluorescent X-ray spectrum. The horizontal axis of FIG. 4 represents the fluorescent X-ray energy, and the vertical axis is a linear scale representing the fluorescent X-ray intensity. For example, the X-ray intensity is expressed as the number of counts per unit time. FIG. 4 also shows the peak of the platinum M-line. The energy of the platinum M-line is defined as the first energy. The energy of the platinum M-line is approximately 2 keV. Fluorescent X-rays having the first energy do not pass through the intermediate layer 43. Although fluorescent X-rays having the first energy are also generated in the second layer 42, these fluorescent X-rays do not pass through the intermediate layer 43 and are therefore not detected by the fluorescent X-ray detector 22. Therefore, the platinum M-line peak included in the fluorescent X-ray spectrum is due to the platinum contained in the first layer 41, and the intensity of the peak is related to the amount of platinum contained in the first layer 41.

[0048] FIG. 5 is a graph showing an example of a transmitted X-ray spectrum. The horizontal axis of FIG. 5 represents the energy of the transmitted X-ray, and the vertical axis is a logarithmic scale representing the intensity of the transmitted X-ray. FIG. 5 also shows the platinum L absorption edge. The energy of the platinum L absorption edge is defined as the second energy. Although there are, strictly speaking, multiple L absorption edges, the energy of any one L absorption edge is defined as the second energy. For example, the energy of the L absorption edge with the greatest intensity among the multiple L absorption edges included in the transmitted X-ray spectrum is defined as the second energy. For example, the LIIIab absorption edge is defined as the L absorption edge used in the process for calculating the amount of platinum. The energy of the platinum LIIIab absorption edge is 11.56 keV. The transmitted X-rays having the second energy are transmitted through the intermediate layer 43. That is, the transmitted X-rays resulting in the platinum L absorption edge are transmitted through the intermediate layer 43 and originate from the platinum contained in the first layer 41 and the second layer 42. Therefore, the intensity of the platinum L absorption edge contained in the spectrum of transmitted X-rays is related to the total amount of platinum contained in the first layer 41 and the second layer 42 .

[0049] FIG. 6 is a flowchart showing an example of a processing procedure executed by the X-ray analysis apparatus 100. Hereinafter, steps are abbreviated as S. The analysis unit 1 executes processing by the calculation unit 11 executing information processing in accordance with the computer program 141. The irradiation unit 3 generates X-rays and irradiates the sample 4 with the X-rays (S1). In S1, the control unit 21 causes the irradiation unit 3 to generate X-rays. The sample 4 is held in the X-ray analysis apparatus 100 so that the X-rays pass through the first layer 41, the intermediate layer 43, and the second layer 42 in that order. Fluorescent X-rays are generated from the first layer 41 by the irradiation of X-rays. The fluorescent X-ray detector 22 detects the fluorescent X-rays (S2). The transmission X-ray detector 23 detects the transmission X-rays that have passed through the sample 4 (S3).

[0050] The fluorescent X-ray detector 22 outputs a signal having an intensity corresponding to the energy of the fluorescent X-rays to the first signal processing unit 24, which counts the signals for each signal value and outputs data indicating the relationship between the signal value and the count number to the analyzing unit 1. The transmitted X-ray detector 23 outputs a signal having an intensity corresponding to the energy of the transmitted X-rays to the second signal processing unit 25, which counts the signals for each signal value and outputs data indicating the relationship between the signal value and the count number to the analyzing unit 1. The analyzing unit 1 acquires the detection results of the fluorescent X-rays and the transmitted X-rays by accepting the data from the first signal processing unit 24 and the second signal processing unit 25 (S4). The calculating unit 11 generates spectra of the fluorescent X-rays and the transmitted X-rays and stores the spectral data in the storage unit 14.

[0051] The analysis unit 1 calculates the amount of platinum contained in the first layer 41 based on the fluorescent X-ray spectrum (S5). In S5, the calculation unit 11 acquires the peak intensity of the platinum M-line contained in the fluorescent X-ray spectrum and calculates the amount of platinum contained in the first layer 41 based on the peak intensity of the platinum M-line. The calculation unit 11 performs the calculation using standard data. For example, the calculation unit 11 compares the peak intensity of the platinum M-line corresponding to a specific platinum amount recorded in the standard data with the acquired peak intensity of the platinum M-line, and calculates the amount of platinum contained in the first layer 41 by interpolating the amount of platinum based on the difference in intensity. In this case, the calculation unit 11 may calculate the amount of platinum per unit area as the amount of platinum, or may calculate the total amount of platinum contained in the entire first layer 41 based on the area and thickness of the first layer 41. The calculation unit 11 stores the calculated amount of platinum contained in the first layer 41 in the memory unit 14.

[0052] The analysis unit 1 calculates the total amount of platinum contained in the first layer 41 and the second layer 42 based on the spectrum of the transmitted X-rays (S6). In S6, the calculation unit 11 calculates the intensity of the platinum L absorption edge contained in the spectrum of the transmitted X-rays. For example, the calculation unit 11 obtains the intensities of two signals located before and after the platinum L absorption edge in the spectrum of the transmitted X-rays, and calculates the difference in intensities of the two obtained signals to calculate the intensity of the platinum L absorption edge. The calculation unit 11 calculates the total amount of platinum contained in the first layer 41 and the second layer 42 according to the intensity of the platinum L absorption edge.

[0053] The calculation unit 11 performs calculations using the standard data. For example, the calculation unit 11 compares the intensity of the platinum L absorption edge corresponding to a specific platinum amount recorded in the standard data with the acquired intensity of the platinum L absorption edge, and interpolates the amount of platinum according to the difference in intensity, thereby calculating the total amount of platinum contained in the first layer 41 and the second layer 42. At this time, the calculation unit 11 may calculate the amount of platinum per unit area, or may calculate the total amount of platinum contained in the first layer 41 and the second layer 42. The calculation unit 11 stores the calculated total amount of platinum contained in the first layer 41 and the second layer 42 in the memory unit 14.

[0054] The analytical unit 1 calculates the amount of platinum contained in the second layer 42 (S7). In S7, the calculation unit 11 calculates the amount of platinum contained in the second layer 42 by subtracting the amount of platinum contained in the first layer 41 from the sum of the amounts of platinum contained in the first layer 41 and the second layer 42. The calculation unit 11 stores the calculated amount of platinum contained in the second layer 42 in the memory unit 14. The calculation unit 11 may display the calculated amounts of platinum contained in each of the first layer 41 and the second layer 42 on the display unit 26. After S7 is completed, the analytical unit 1 ends the processing.

[0055] Next, the X-rays irradiated onto the sample 4 by the irradiation unit 3 will be described. FIG. 7 is a schematic diagram showing an example of the configuration of the irradiation unit 3. The irradiation unit 3 includes an X-ray generation unit 30 that generates X-rays. The X-ray generation unit 30 is an X-ray tube. The X-ray generation unit 30 has a filament 31, a target 32, a sealing tube 33, a power supply 34, and a voltage application unit 35. The sealing tube 33 is transparent, and is sealed with the filament 31 and the target 32 ​​housed inside. The filament 31 and the target 32 ​​face each other. The power supply 34 is connected to the filament 31.

[0056] A current flows through the filament 31 from a power supply 34, causing the filament 31 to generate heat, which generates electrons from the filament 31. A voltage application unit 35 applies a voltage between the filament 31 and the target 32 ​​to accelerate the electrons generated from the filament 31 toward the target 32. The target 32 ​​is made of, for example, copper. The electrons generated from the filament 31 are accelerated by the voltage and collide with the target 32, generating X-rays. In Figure 7, the trajectories of the electrons are indicated by dashed arrows, and the X-rays are indicated by solid arrows.

[0057] The irradiation unit 3 irradiates the sample 4 with X-rays generated by the X-ray generation unit 30. The energy range of the X-rays irradiated to the sample 4 depends on the voltage applied by the voltage application unit 35. For example, if an arbitrary positive value is A and the magnitude of the voltage applied by the voltage application unit 35 is AkV, the energy of the X-rays irradiated to the sample 4 is continuously distributed in a range of AkeV or less. The X-ray generation unit 30 determines the magnitude of the voltage applied by the voltage application unit 35. For example, the magnitude of the voltage applied by the voltage application unit 35 is fixed in advance. For example, the voltage application unit 35 is connected to the control unit 21, and the control unit 21 controls the magnitude of the voltage applied by the voltage application unit 35.

[0058] The energy ranges of the fluorescent X-rays and the transmitted X-rays depend on the energy range of the X-rays irradiated onto the sample 4. To obtain the fluorescent X-rays and the transmitted X-rays, irradiation with X-rays having higher energy is necessary. That is, to observe a peak included in the spectrum of the fluorescent X-rays or an absorption edge included in the spectrum of the transmitted X-rays, irradiation with X-rays having an energy higher than the energy of the peak or absorption edge is necessary. In this embodiment, irradiation with X-rays having an energy higher than the second energy is necessary.

[0059] The transmitted X-rays detected by the transmission X-ray detector 23 contain fluorescent X-rays. Therefore, the spectrum of the transmitted X-rays contains peaks of fluorescent X-rays. In the spectrum of the transmitted X-rays, the peak of the L-rays of platinum's fluorescent X-rays appears close to the platinum's L-absorption edge, and the L-ray peak affects the intensity of the L-absorption edge. The energy of the platinum L-ray peak is slightly lower than the energy of the platinum L-absorption edge. The more X-rays having energies higher than the fluorescent X-ray peak and absorption edge are irradiated onto the sample 4, the greater the intensity of the fluorescent X-ray peak and the intensity of the absorption edge. The higher the maximum energy of the X-rays irradiated onto the sample 4, the greater the intensity of the X-rays having each energy.

[0060] In order to accurately calculate the intensity of the platinum L absorption edge, it is desirable that the sample 4 be irradiated with X-rays having an energy higher than the L absorption edge at a sufficiently high intensity, so that the intensity of the L absorption edge is sufficiently high. To achieve this, the maximum energy of the X-rays irradiated to the sample 4 must be higher than the second energy, which is the energy of the platinum L absorption edge, and the X-rays having an energy higher than the second energy must be irradiated to the sample 4 at a sufficiently high intensity. However, if the intensity of the X-rays having an energy higher than the second energy is high, the intensity of the L rays of the platinum fluorescent X-rays also becomes high, affecting the intensity of the L absorption edge. For this reason, it is desirable that the intensity of the X-rays having an energy higher than the second energy is not too high, and it is also desirable that the maximum energy of the X-rays irradiated to the sample 4 is not too high.

[0061] The maximum energy value of the X-rays irradiated onto the sample 4 is set as the third energy. That is, the maximum energy value of the X-rays generated by the X-ray generation unit 30 is the third energy. In this embodiment, the third energy is higher than the second energy. The third energy is set to a value that prevents the intensity of the L-rays of platinum fluorescent X-rays from becoming too high. The third energy is determined by setting the magnitude of the voltage that the voltage application unit 35 applies to the filament 31 and the target 32 ​​to a predetermined value.

[0062] 8 and 9 are graphs showing examples of spectra of transmitted X-rays obtained when the voltage applied by the voltage application unit 35 is different from that shown in FIG. 5 . The horizontal axis of FIGS. 8 and 9 indicates the energy of the transmitted X-rays, and the vertical axis is a logarithmic scale and indicates the intensity of the transmitted X-rays. FIG. 8 shows an example in which the magnitude of the voltage applied by the voltage application unit 35 is 12 kV, FIG. 5 shows an example in which the magnitude of the voltage applied by the voltage application unit 35 is 13 kV, and FIG. 9 shows an example in which the magnitude of the voltage applied by the voltage application unit 35 is 15 kV. That is, in the example shown in FIG. 8 , the third energy is 12 keV, in the example shown in FIG. 5 , the third energy is 13 keV, and in the example shown in FIG. 9 , the third energy is 15 keV.

[0063] As shown in Figures 5, 8, and 9, the spectrum of the transmitted X-rays includes the L absorption edge of platinum. The L absorption edge in the figures is the LIIIab absorption edge, and its energy is 11.56 keV. Since the spectrum of the transmitted X-rays includes the L absorption edge of platinum, the X-ray analysis apparatus 100 can perform processes S1 to S7 and measure the amount of platinum contained in the first layer 41 and the second layer 42 of the sample 4. It is desirable that the third energy be an appropriate value that allows accurate measurement of the intensity of the L absorption edge and sufficiently reduces the intensity of the fluorescent X-ray L rays.

[0064] As shown in FIG. 8 , when the third energy is 12 keV, the transmission spectrum contains few signals with energies higher than the platinum L absorption edge. This results in a relatively inaccurate L absorption edge intensity. Thus, when the difference between the third energy and the second energy is less than 1 keV, the L absorption edge intensity is inaccurate. Therefore, it is desirable that the difference between the third energy and the second energy be 1 keV or greater. Furthermore, as shown in FIG. 9 , when the third energy is 15 keV, the intensity of the L line of the platinum fluorescent X-rays increases, significantly increasing the influence of the L line on the L absorption edge intensity. This results in a relatively inaccurate L absorption edge intensity. Thus, even when the difference between the third energy and the second energy exceeds 3 keV, the L absorption edge intensity is inaccurate. Therefore, it is desirable that the difference between the third energy and the second energy be 3 keV or less. Therefore, it is desirable that the third energy be 1 to 3 keV higher than the second energy.

[0065] As shown in FIG. 5 , when the third energy is 13 keV, the transmission spectrum contains sufficient signals with energies higher than the platinum L-absorption edge. Furthermore, the intensity of the platinum L-line fluorescent X-rays is sufficiently low, so the influence of the L-line on the intensity of the L-absorption edge is small. Therefore, when the third energy is 1 to 3 keV higher than the second energy, the analysis unit 1 can more accurately calculate the intensity of the L-absorption edge, thereby enabling more accurate calculation of the amount of platinum contained in the first layer 41 and the second layer 42 of the sample 4. The magnitude of the voltage applied by the voltage application unit 35 is set so that the third energy is 1 to 3 keV higher than the second energy. For example, when the third energy is 13 keV, the magnitude of the voltage is 13 kV. By appropriately setting the magnitude of the voltage applied by the voltage application unit 35 so that the third energy is an appropriate value, the X-ray analysis apparatus 100 can accurately measure the amount of platinum contained in the first layer 41 and the second layer 42 of the sample 4.

[0066] As described above in detail, in this embodiment, the X-ray analysis apparatus 100 irradiates the sample 4 with X-rays, detects fluorescent X-rays generated from the first layer 41, and detects transmitted X-rays that have passed through the sample 4. The analysis unit 1 calculates the amount of platinum contained in the first layer 41 according to the intensity of the fluorescent X-rays that do not pass through the intermediate layer 43. The analysis unit 1 calculates the total amount of platinum contained in the first layer 41 and the second layer 42 according to the intensity of the fluorescent X-rays that have passed through the intermediate layer 43. The analysis unit 1 calculates the amount of platinum contained in the second layer 42 from the amount of platinum contained in the first layer 41 and the sum of the amounts of platinum contained in the first layer 41 and the second layer 42. This enables the X-ray analysis apparatus 100 to individually measure the amounts of platinum contained in the first layer 41 and the second layer 42 of the multilayer sample 4.

[0067] For example, the sample 4 may be incorporated into a fuel cell, with the intermediate layer 43 functioning as an electrolyte membrane and the first layer 41 and the second layer 42 functioning as catalyst layers. The X-ray analysis device 100 can measure the amount of platinum contained in each catalyst layer individually. The performance of the fuel cell can be estimated based on the measured amount of platinum.

[0068] Although the above description illustrates a configuration in which the amount of platinum contained in the first layer 41 and the second layer 42 is measured, the X-ray analysis apparatus 100 may also be configured to measure the amount of an element other than platinum. For example, the first layer 41 and the second layer 42 contain iridium as a specific element, and the X-ray analysis apparatus 100 measures the amount of iridium contained in the first layer 41 and the second layer 42. Like platinum, iridium can be used as a catalyst. In S5, the analysis unit 1 calculates the amount of iridium contained in the first layer 41 based on the intensity of the iridium M-ray peak in the fluorescent X-ray spectrum. In S6, the analysis unit 1 calculates the sum of the amounts of iridium contained in the first layer 41 and the second layer 42 based on the intensity of the iridium L-absorption edge in the transmitted X-ray spectrum. In S7, the analysis unit 1 calculates the amount of iridium contained in the second layer 42. In this way, through the processes of S1 to S7, the X-ray analysis apparatus 100 measures the amount of iridium contained in the first layer 41 and the second layer 42. Based on the measured amount of iridium, the performance of the fuel cell can be estimated.

[0069] The first layer 41 and the second layer 42 may contain ruthenium, rhodium, or palladium as a specific element, and the X-ray analysis apparatus 100 may measure the amount of ruthenium, rhodium, or palladium contained in the first layer 41 and the second layer 42. Ruthenium, rhodium, or palladium may also be used as a catalyst. When the specific element is ruthenium, rhodium, or palladium, the energy of the L-line of ruthenium, rhodium, or palladium contained in the fluorescent X-ray spectrum is defined as the first energy. Although there are, strictly speaking, multiple L-lines, the energy of any one L-line is defined as the first energy. For example, the energy of the L-line with the greatest intensity among the multiple L-lines is defined as the first energy. For example, the Lα line is defined as the L-line used in the process for calculating the amount of ruthenium, rhodium, or palladium. The energies of the Lα lines of ruthenium, rhodium, and palladium are 2.558 keV, 2.696 keV, and 2.838 keV, respectively. The fluorescent X-rays having this first energy do not pass through the intermediate layer 43 .

[0070] When the specific element is ruthenium, rhodium, or palladium, the energy of the K-absorption edge included in the spectrum of the transmitted X-ray is set as the second energy. The K-absorption edge energies of ruthenium, rhodium, and palladium are 22.116 keV, 23.216 keV, and 24.344 keV, respectively. Fluorescent X-rays having this second energy are transmitted through the intermediate layer 43.

[0071] In S5, the analysis unit 1 calculates the amount of ruthenium, rhodium, or palladium contained in the first layer 41 according to the intensity of the L-line peak of ruthenium, rhodium, or palladium contained in the fluorescent X-ray spectrum. In S6, the analysis unit 1 calculates the total amount of ruthenium, rhodium, or palladium contained in the first layer 41 and the second layer 42 according to the intensity of the K-absorption edge of ruthenium, rhodium, or palladium contained in the transmitted X-ray spectrum. In S7, the analysis unit 1 calculates the amount of ruthenium, rhodium, or palladium contained in the second layer 42. In this way, by the processes of S1 to S7, the X-ray analysis apparatus 100 measures the amount of ruthenium, rhodium, or palladium contained in the first layer 41 and the second layer 42. The performance of the fuel cell can be estimated based on the measured amount of ruthenium, rhodium, or palladium.

[0072] While the present embodiment illustrates a configuration in which fluorescent X-rays generated from the first layer 41 are detected, the X-ray analysis apparatus 100 may also be configured to detect fluorescent X-rays generated from the second layer 42. FIG. 10 is a block diagram showing an example of the functional configuration of an X-ray analysis apparatus 100 according to another embodiment. The X-ray fluorescence detector 22 is disposed to face the rear surface of the sample 4. The configuration of other parts of the X-ray analysis apparatus 100 is similar. In this embodiment, in S2, the X-ray fluorescence detector 22 detects fluorescent X-rays generated from the second layer 42. In S5, the analysis unit 1 calculates the amount of the specific element contained in the second layer 42. In S7, the analysis unit 1 calculates the amount of the specific element contained in the first layer 41 from the amount of the specific element contained in the second layer 42 and the sum of the amounts of the specific element contained in the first layer 41 and the second layer 42. Even in this embodiment, the X-ray analysis apparatus 100 can individually measure the amounts of the specific element contained in each of the first layer 41 and the second layer 42.

[0073] The X-ray analysis apparatus 100 may have a configuration in which the X-ray fluorescence detector 22 and the transmission X-ray detector 23 are integrated into one detector. The transmission X-ray detector 23 also detects fluorescent X-rays generated from the second layer 42. In this configuration, the X-ray analysis apparatus 100 does not include the X-ray fluorescence detector 22 or the first signal processing unit 24, and the transmission X-ray detector 23 also functions as the X-ray fluorescence detector 22. In this configuration, the X-ray analysis apparatus 100 does not perform the process of S2. In S5, the analysis unit 1 acquires the intensity of a peak of fluorescent X-rays having a first energy included in the spectrum of transmitted X-rays, and calculates the amount of the specific element included in the second layer 42 based on the acquired intensity. In S7, the analysis unit 1 calculates the amount of the specific element included in the first layer 41 from the amount of the specific element included in the second layer 42 and the sum of the amounts of the specific element included in the first layer 41 and the second layer 42. In this manner, even in this configuration, the X-ray analysis apparatus 100 can measure the amounts of specific elements contained in the first layer 41 and the second layer 42 individually.

[0074] The X-ray analysis apparatus 100 may be configured to separately detect the fluorescent X-rays generated from the first layer 41 and the fluorescent X-rays generated from the second layer 42. In this configuration, the X-ray analysis apparatus 100 includes two X-ray fluorescence detectors 22, one of which detects the fluorescent X-rays generated from the first layer 41, and the other of which detects the fluorescent X-rays generated from the second layer 42. In this configuration, the transmission X-ray detector 23 may also function as the X-ray fluorescence detector 22 that detects the fluorescent X-rays generated from the second layer 42.

[0075] In this embodiment, the X-ray analysis apparatus 100 individually detects fluorescent X-rays emitted from the first layer 41 and the second layer 42 in S2. In S5 to S7, the analysis unit 1 calculates the amount of a specific element contained in each of the first layer 41 and the second layer 42 using the intensities of the detected fluorescent X-rays emitted from the first layer 41 and the second layer 42 and the intensities of the detected transmitted X-rays. For example, the analysis unit 1 calculates the ratio of the amount of the specific element contained in the first layer 41 to the amount of the specific element contained in the second layer 42 based on the intensities of the detected fluorescent X-rays emitted from the first layer 41 and the second layer 42. The analysis unit 1 also calculates the amount of the specific element contained in each of the first layer 41 and the second layer 42 from the ratio of the amount of the specific element to the total amount of the specific element contained in the first layer 41 and the second layer 42. Thus, even in this embodiment, the X-ray analysis apparatus 100 can individually measure the amount of the specific element contained in each of the first layer 41 and the second layer 42.

[0076] In the present embodiment, the X-ray fluorescence detector 22 and the transmission X-ray detector 23 are radiation detectors having radiation detection elements formed using semiconductors. The X-ray fluorescence detector 22 and the transmission X-ray detector 23 may also be radiation detectors having radiation detection elements other than those formed using semiconductors. The X-ray fluorescence detector 22 and the transmission X-ray detector 23 are not limited to energy dispersive detectors, and may be detectors that can detect the intensity of X-rays of a specific energy. In the present embodiment, an example has been shown in which the horizontal axis of the X-ray spectrum is energy, but the X-ray analysis apparatus 100 may also be configured to handle spectra in which the horizontal axis is a value other than energy, such as wavelength or wave number.

[0077] The present invention is not limited to the contents of the above-described embodiment, and various modifications are possible within the scope of the claims. In other words, embodiments obtained by combining technical means modified appropriately within the scope of the claims are also included in the technical scope of the present invention.

[0078] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any and all combinations, regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used.

[0079] REFERENCE SIGNS LIST 100 X-ray analysis apparatus 1 Analysis unit (information processing device) 10 Recording medium 11 Calculation unit 14 Storage unit 141 Computer program 22 Fluorescence X-ray detector 23 Transmission X-ray detector 3 Irradiation unit 30 X-ray generation unit 31 Filament 32 Target 35 Voltage application unit 4 Sample 41 First layer 42 Second layer 43 Intermediate layer

Claims

1. An X-ray analysis apparatus comprising: an irradiation unit which irradiates a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first and second layers, with X-rays so as to penetrate the first layer, the intermediate layer, and the second layer in that order; an X-ray fluorescence detector which detects fluorescent X-rays generated from the first layer or the second layer; a transmission X-ray detector which detects transmitted X-rays which have transmitted through the sample; and an analysis unit, the analysis unit calculates an amount of a specific element contained in either the first layer or the second layer in accordance with the intensity of the fluorescent X-rays which are contained in the fluorescent X-rays detected by the X-ray fluorescence detector and have a predetermined first energy; calculates a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with the intensity of the transmitted X-rays which are contained in the transmitted X-rays detected by the transmission X-ray detector and have a predetermined second energy which is higher than the first energy; and calculates the amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in either the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

2. The X-ray analysis apparatus according to claim 1, characterized in that the first energy is the energy of fluorescent X-rays originating from a specific electron shell, and the second energy is the energy of an absorption edge originating from an electron shell one shell outside the specific electron shell.

3. The X-ray analysis apparatus according to claim 1 or 2, characterized in that the irradiation unit has an X-ray generation unit that generates X-rays by colliding accelerated electrons with a target, and the X-ray generation unit determines the magnitude of a voltage for accelerating electrons so that the maximum energy of the generated X-rays becomes a predetermined third energy higher than the second energy.

4. The X-ray analysis apparatus according to claim 3, wherein the third energy is 1 to 3 keV higher than the second energy.

5. An X-ray analysis apparatus as described in any one of claims 1 to 4, characterized in that the specific element is platinum or iridium, and the analysis unit calculates the amount of platinum or iridium contained in one of the first layer or the second layer depending on the intensity of the M-ray of platinum or iridium contained in the fluorescent X-rays detected by the fluorescent X-ray detector, and calculates the total amount of platinum or iridium contained in the first layer and the second layer depending on the intensity of the L-absorption edge of platinum or iridium contained in the transmitted X-rays detected by the transmitted X-ray detector.

6. An X-ray analysis apparatus as described in any one of claims 1 to 4, characterized in that the specific element is ruthenium, rhodium or palladium, and the analysis unit calculates the amount of ruthenium, rhodium or palladium contained in one of the first layer or the second layer depending on the intensity of the L-lines of ruthenium, rhodium or palladium contained in the fluorescent X-rays detected by the fluorescent X-ray detector, and calculates the total amount of ruthenium, rhodium or palladium contained in the first layer and the second layer depending on the intensity of the K-absorption edge of ruthenium, rhodium or palladium contained in the transmitted X-rays detected by the transmitted X-ray detector.

7. A method of X-ray analysis comprising the steps of: irradiating a sample having a plurality of laminated layers, the sample including a first layer, a second layer, and an intermediate layer located between the first layer and the second layer, with X-rays so as to penetrate the first layer, the intermediate layer, and the second layer in that order; detecting fluorescent X-rays generated from the first layer or the second layer; detecting transmitted X-rays that have transmitted through the sample; calculating an amount of a specific element contained in either the first layer or the second layer in accordance with the intensity of the fluorescent X-rays having a predetermined first energy that are contained in the detected fluorescent X-rays; calculating a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with the intensity of the transmitted X-rays having a predetermined second energy higher than the first energy that are contained in the detected transmitted X-rays; and calculating an amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in either the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

8. The X-ray analysis method according to claim 7, characterized in that the intermediate layer is a polymer film, and the first layer and the second layer are catalyst layers containing platinum, iridium, ruthenium, rhodium or palladium.

9. An information processing device comprising a calculation unit, the calculation unit: irradiating a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first layer and the second layer with X-rays so as to penetrate the first layer, the intermediate layer, and the second layer in that order; obtaining a result of detecting fluorescent X-rays generated from the first layer or the second layer and a result of detecting transmitted X-rays that have penetrated the sample; calculating an amount of a specific element contained in either the first layer or the second layer in accordance with the intensity of the fluorescent X-rays that are contained in the detected fluorescent X-rays and have a predetermined first energy; calculating a sum of the amounts of the specific element contained in the first layer and the second layer in accordance with the intensity of the transmitted X-rays that are contained in the detected transmitted X-rays and have a predetermined second energy higher than the first energy; and calculating an amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in either the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

10. A computer program causing a computer to execute the following processes: irradiating a sample having a plurality of stacked layers, the sample including a first layer, a second layer, and an intermediate layer located between the first layer and the second layer, with X-rays penetrating the first layer, the intermediate layer, and the second layer in that order; calculating, based on the result of detecting fluorescent X-rays generated from the first layer or the second layer, the amount of a specific element contained in one of the first layer or the second layer in accordance with the intensity of the fluorescent X-rays having a predetermined first energy that are contained in the detected fluorescent X-rays; calculating, based on the result of detecting transmitted X-rays that have transmitted through the sample, the sum of the amounts of the specific element contained in the first layer and the second layer in accordance with the intensity of the transmitted X-rays having a predetermined second energy higher than the first energy; and calculating the amount of the specific element contained in the other of the first layer or the second layer in accordance with the amount of the specific element contained in the first layer or the second layer and the sum of the amounts of the specific element contained in the first layer and the second layer.

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