A raman spectroscopy-based pressure calculation method and system
By constructing a pressure standard model using Raman spectroscopy, the problem of pressure measurement deviation in high-temperature and high-pressure experiments has been solved, achieving higher accuracy and a wider applicable pressure range, supporting deep crustal research, and providing a more reliable quantitative tool.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- UNIV OF SCI & TECH BEIJING
- Filing Date
- 2026-02-13
- Publication Date
- 2026-06-16
Smart Images
Figure CN122217533A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high temperature and high pressure experimental technology, and in particular to a pressure calculation method and system based on Raman spectroscopy. Background Technology
[0002] In the study of deep Earth mineralization processes, high-temperature and high-pressure (HTHP) experiments are a commonly used method. Early HTHP experiments primarily involved non-in-situ (i.e., real-time observation of the experimental system during processes that could not be directly performed by the researcher) experiments. This involved quenching samples subjected to high temperatures and pressures before studying the system. However, the composition of quenched samples can differ significantly from that of samples under HTHP conditions. In contrast, in-situ experimental devices, such as hydrothermal diamond anvil cells (HDACs) and fused silica capillary capsules (FSCCs), possess light-transmitting reaction chambers. These devices allow for direct measurement of internal samples at the experimental temperatures and pressures of interest using instruments like Raman spectrometers, and real-time spectral acquisition.
[0003] However, compared to non-in-situ devices, in-situ devices cannot simultaneously and independently control the system's temperature and pressure. Taking HDAC and FSCC as examples, the internal pressure of their systems increases with increasing temperature, and while the system temperature can be directly obtained from the thermocouples in the device, its internal pressure cannot be directly measured.
[0004] To determine internal pressure, different equations of state are typically used. However, experimental systems are more complex than those described by these equations of state (EOS). When determining internal pressure using equations of state, it is necessary to assume that the solute concentration in the experimental system is the same as that in the equation of state, which inevitably leads to significant deviations in pressure measurement. Furthermore, HDAC and FSCC may experience volume expansion during the experiment, which does not conform to the constant pressure assumption of the equations of state.
[0005] Besides equations of state, certain minerals can also be used as pressure sensors to determine the internal pressure of in-situ devices. Because the Raman displacements of these minerals are sensitive to changes in temperature and pressure conditions, the internal pressure can be determined by measuring the contrast between the Raman displacements under ambient temperature and pressure and those under target temperature and pressure conditions.
[0006] In high-temperature and high-pressure experiments, accurately determining the pressure information of the system is particularly important. Existing techniques typically calculate the pressure of the system using different equations of state or specific minerals in the system.
[0007] Equations of state are typically only applicable to simple multivariate systems and require ideal conditions. However, experimental systems are far more complex than those described by these equations of state (EoS). Using EoS to determine internal pressure requires assuming the solute composition in the experimental system is identical to that in the EoS, inevitably leading to significant deviations in pressure measurements. Furthermore, while EoS is intended for determining pressure in isochoric systems, the volume of the sample chamber in in-situ experimental setups changes drastically under high temperature and pressure conditions. Existing research shows that thermal expansion can increase the volume of a rapidly quenched, cold-sealed sample chamber by up to 75% at temperatures exceeding 400 °C. Therefore, using EoS under high temperature and pressure conditions results in severely biased pressure measurements (Chou, 2008). Thus, relying solely on EoS is insufficient to accommodate the diverse experimental conditions and natural samples.
[0008] For pressure gauges, taking the zircon ν3(SiO4)-1008 peak pressure gauge as an example, existing technologies have calibrated the relationship between this peak position and PT (Pressure Tolerance), and developed pressure sensors suitable for high-temperature and high-pressure experiments with an accuracy of ±50 MPa. However, this pressure measurement method is only applicable to zircon particles whose ν3(SiO4) Raman shift is strictly located at or close to 1008.17 cm⁻¹ at room temperature (25°C). For various natural or synthetic zircon particles, their ν3(SiO4) Raman shift at room temperature may exhibit varying degrees of positive or negative bias relative to 1008, which will lead to significant deviations in pressure measurements. Summary of the Invention
[0009] To address the aforementioned technical problems in existing technologies, embodiments of the present invention provide a pressure calculation method and system based on Raman spectroscopy. The technical solution is as follows: On one hand, a pressure calculation method based on Raman spectroscopy is provided. The method includes: obtaining a first Raman shift relative to a preset peak position in the Raman spectrum of a test sample under target experimental conditions; the test sample includes zircon and quartz; the target experimental conditions include a target temperature value and a test pressure value; obtaining a second Raman shift relative to the preset peak position in the Raman spectrum of the test sample under ambient temperature and pressure conditions; constructing a pressure scale model of the test sample based on the preset peak position in the Raman spectrum; and substituting the first Raman shift, the second Raman shift, and the target temperature value into the pressure scale model to calculate the test pressure value.
[0010] Optionally, when the test sample is zircon, the indentation model includes:
[0011] In the formula, The ν3(SiO4) Raman shift of zircon under the target experimental conditions is given. The value represents the ν3(SiO4) Raman displacement of zircon under normal temperature and pressure conditions, where T is the target temperature and P is the pressure to be measured.
[0012] Optionally, when the test sample is quartz and the preset peak position is the 464 Raman peak, the pressure standard model includes:
[0013] In the formula, The displacement of the 464 Raman peak in quartz under the target experimental conditions. The value represents the displacement of the 464 Raman peak of quartz under normal temperature and pressure conditions, where T is the target temperature and P is the pressure to be measured.
[0014] Optionally, when the test sample is quartz and the preset peak position is the 206 Raman peak, the pressure standard model includes:
[0015] In the formula, The displacement of the 206 Raman peak of quartz under the target experimental conditions. The displacement of the 206 Raman peak of quartz under normal temperature and pressure conditions is given by T, where T is the target temperature and P is the pressure to be measured.
[0016] Optionally, when the test sample is quartz and the preset peak position is the 128 Raman peak, the pressure standard model includes:
[0017] In the formula, The displacement of the 128 Raman peak of quartz under the target experimental conditions. The displacement of the 128 Raman peak of quartz under normal temperature and pressure conditions is given by T, where T is the target temperature and P is the pressure to be measured.
[0018] On the other hand, embodiments of the present invention also provide a pressure calculation system based on Raman spectroscopy, used to implement a pressure calculation method based on Raman spectroscopy provided in embodiments of the present invention; the system includes: a first acquisition module, a second acquisition module, a construction module, and a calculation module; wherein, the first acquisition module is used to acquire the first Raman shift of the test sample relative to a preset peak position in the Raman spectrum of the test sample under target experimental conditions; the test sample includes zircon and quartz; the target experimental conditions include a target temperature value and a test pressure value; the second acquisition module is used to acquire the second Raman shift of the test sample relative to the preset peak position in the Raman spectrum of the test sample under normal temperature and pressure conditions; the construction module is used to construct a pressure scale model of the test sample based on the preset peak position in the Raman spectrum; the calculation module is used to substitute the first Raman shift, the second Raman shift, and the target temperature value into the pressure scale model to calculate the test pressure value.
[0019] On the other hand, an electronic device is also provided, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method provided in the embodiments of the present invention.
[0020] On the other hand, a computer-readable storage medium is also provided, wherein program code is stored in the computer-readable storage medium, and the program code can be called by a processor to execute the method provided in the embodiments of the present invention.
[0021] This invention provides a pressure calculation method and system based on Raman spectroscopy. By constructing a pressure scale model under high temperature and high pressure conditions, the accuracy of Raman spectroscopy pressure measurement under high temperature and high pressure conditions is improved, alleviating the technical problem of deviation values in pressure measurement values under high temperature and high pressure in existing technologies. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a flowchart of a pressure calculation method based on Raman spectroscopy provided in an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the pressure calculation error between the zircon indentation model provided in this embodiment of the invention and existing indentation models; Figure 3This is a schematic diagram illustrating the pressure calculation error between the quartz pressure gauge model provided in this embodiment of the invention and existing pressure gauge models; Figure 4 This is a schematic diagram of a pressure calculation system based on Raman spectroscopy provided in an embodiment of the present invention. Detailed Implementation
[0024] The technical solution of the present invention will now be described with reference to the accompanying drawings.
[0025] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.
[0026] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.
[0027] Figure 1 This is a flowchart of a pressure calculation method based on Raman spectroscopy provided according to an embodiment of the present invention. Figure 1 As shown, the method specifically includes the following steps: Step S102: Obtain the first Raman shift of the test sample relative to the preset peak position in the Raman spectrum of the test sample under the target experimental conditions; the test sample includes zircon and quartz; the target experimental conditions include the target temperature value and the test pressure value.
[0028] Step S104: Obtain the second Raman shift relative to the preset peak position in the Raman spectrum of the test sample under normal temperature and pressure conditions.
[0029] Specifically, normal temperature and pressure conditions include room temperature (25°C) and standard atmospheric pressure conditions.
[0030] Step S106: Based on the preset peak positions in the Raman spectrum, construct the pressure model of the sample to be tested.
[0031] Step S108: Substitute the first Raman displacement, the second Raman displacement, and the target temperature value into the pressure gauge model to calculate the pressure value to be measured.
[0032] The principle of pressure gauge measurement is as follows: Assuming the target mineral (hereinafter referred to as the pressure sensor) has a temperature of T0 under normal temperature and pressure, and the measured Raman displacement is ν... P0,T0 Under the experimental conditions that achieved the research objectives, at a temperature of T, the measured Raman shift was ν. P,T The total Raman displacement change νP,T The difference between the two measured Raman displacements: Δν(P,T)=ν P,T -ν P0,T0 =Δν P +Δν T +Δν PT In the formula Δν P ,Δν T Δν represents the Raman displacement changes caused by pressure and temperature, respectively. PT This represents the change in Raman displacement caused by the combined effect of temperature and pressure, obtained by taking the partial derivatives of the Raman displacement with respect to temperature and pressure: Δν PT = ( 2ν / P T)dPdT The Raman shift of minerals typically changes with increasing temperature and pressure; therefore, the Raman shift can be considered a function of temperature and pressure. ν P,T =f(T,P) The Raman displacement change caused by temperature / pressure can be expressed as the partial derivatives of the Raman displacement with respect to temperature / pressure:
[0033] In obtaining Δν T Then, given a specific temperature and pressure, the other terms can be solved. This allows for the calculation of the pressure value under the corresponding system conditions.
[0034] In practice, fitting the Raman peak displacement to both temperature and pressure is a simpler calculation method. First, the Raman peak displacement at different temperatures is measured through a normal pressure, high temperature experiment, and then the curve of the Raman peak displacement versus temperature is obtained through regression analysis. Δν T =f(T) Similarly, by measuring the Raman peak displacement of minerals under different pressures through room temperature and high pressure experiments, the relationship between pressure and Raman peak displacement can be derived through regression analysis. P=f(Δν P ) Based on the above fitting results, the Raman displacement change Δν caused by the combined effect of temperature and pressure can be obtained. PT The pressure calculation prefit model of the pressure sensor Raman peak displacement under the premise of "zero".
[0035] Based on the above fundamental principles, this embodiment of the invention constructs a zircon indentation model under high temperature and high pressure conditions. That is, when the test sample is zircon, the indentation model includes:
[0036] In the formula, The target experimental conditions are the ν3(SiO4) Raman shifts of zircon. The value represents the ν3(SiO4) Raman displacement of zircon under normal temperature and pressure conditions, where T is the target temperature and P is the pressure to be measured.
[0037] Preferably, the zircon in the embodiments of the present invention includes natural zircon samples and synthetic zircon samples.
[0038] Figure 2 This is a schematic diagram illustrating the pressure calculation error between the zircon indentation model provided according to an embodiment of the present invention and existing indentation models. Figure 2 It is known that existing pressure calibration models (i.e., previous methods) have an error of ±10% to 30% compared to the zircon pressure calibration model in this application. Under high pressure, the existing pressure calculation methods have an error of up to 10% compared to the actual pressure. Given the already high pressure base, a 10% error already makes the calculation results unusable for subsequent analysis. However, this invention, based on fitting high-temperature and high-pressure zircon Raman displacement data, can avoid the above-mentioned errors and obtain more accurate system pressure calculation results.
[0039] This invention also constructs a pressure benchmark model for quartz under high temperature and high pressure. Specifically, when the test sample is quartz and the preset peak position is the 464 Raman peak, the pressure benchmark model includes:
[0040] In the formula, The displacement of the 464 Raman peak in quartz under the target experimental conditions. The value represents the displacement of the 464 Raman peak of quartz under normal temperature and pressure conditions, where T is the target temperature and P is the pressure to be measured.
[0041] Specifically, when the test sample is quartz and the preset peak position is the 206 Raman peak, the pressure calibration model includes:
[0042] In the formula, The displacement of the 206 Raman peak in quartz under the target experimental conditions. The displacement of the 206 Raman peak of quartz under normal temperature and pressure conditions is given by T, where T is the target temperature and P is the pressure to be measured.
[0043] Specifically, when the test sample is quartz and the preset peak position is the 128 Raman peak, the pressure model includes:
[0044] In the formula, The displacement of the 128 Raman peak in quartz under the target experimental conditions. The displacement of the 128 Raman peak of quartz under normal temperature and pressure conditions is given by T, where T is the target temperature and P is the pressure to be measured.
[0045] Figure 3 This is a schematic diagram illustrating the pressure calculation error between the quartz pressure gauge model provided according to an embodiment of the present invention and existing pressure gauge models. Figure 3 It is known that the existing results have a large error in the pressure range shown in the figure (0-806 MPa). The quartz pressure gauge model proposed in this invention can expand the pressure calculation to a larger pressure range and achieve higher accuracy.
[0046] This invention provides a pressure calculation method based on Raman spectroscopy, establishing a universal pressure scale model applicable to both natural and synthetic zircon samples. Compared to existing pressure scale models, its applicable pressure ranges from 6600 bar to 8060 bar. Simultaneously, a quartz pressure scale model is also established, extending the applicable pressure range of the quartz ν206 pressure scale by more than three times from 0-2500 bar to 0-9100 bar, and extending the applicable pressure range of other quartz peak shift pressure scales from 2100 bar to 9100 bar. This invention significantly improves the depth and accuracy of this technology in the field of Earth sciences, enabling in-situ experimental simulations to cover key temperature and pressure conditions from the middle and lower crust to near the Moho discontinuity (approximately 30-35 km depth). This directly supports high-pressure experimental research on deep crustal metamorphism, fluid activity, magmatic evolution, and mineralization processes, filling the pressure gap between shallow crustal and mantle scale studies, and providing a more reliable quantitative tool for mineral resource exploration, geodynamic modeling, and understanding deep geological processes.
[0047] Figure 4 This is a schematic diagram of a pressure calculation system based on Raman spectroscopy according to an embodiment of the present invention. Figure 4 As shown, the system includes: a first acquisition module 10, a second acquisition module 20, a construction module 30, and a calculation module 40.
[0048] Specifically, the first acquisition module 10 is used to acquire the first Raman shift of the test sample relative to the preset peak position in the Raman spectrum of the test sample under the target experimental conditions; the test sample includes zircon and quartz; the target experimental conditions include the target temperature value and the test pressure value; The second acquisition module 20 is used to acquire the second Raman shift of the test sample relative to the preset peak position in the Raman spectrum under normal temperature and pressure conditions; Module 30 is used to construct a pressure model of the sample to be tested based on the preset peak positions in the Raman spectrum. The calculation module 40 is used to substitute the first Raman displacement, the second Raman displacement and the target temperature value into the pressure scale model to calculate the pressure value to be measured.
[0049] The present invention also provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method provided in the embodiments of the present invention.
[0050] The present invention also provides a computer-readable storage medium storing program code, which can be called by a processor to execute the method provided in the embodiments of the present invention.
[0051] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.
[0052] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.
[0053] In the several embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.
[0054] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0055] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.
[0056] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0057] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A pressure calculation method based on Raman spectroscopy, characterized in that, The method includes: The first Raman shift relative to a preset peak position is obtained in the Raman spectrum of the test sample under target experimental conditions; the test sample includes zircon and quartz; the target experimental conditions include target temperature and test pressure. Obtain the second Raman shift of the test sample relative to the preset peak position in the Raman spectrum under normal temperature and pressure conditions; Based on the preset peak positions in the Raman spectrum, a pressure model of the sample to be tested is constructed. The first Raman displacement, the second Raman displacement, and the target temperature value are substituted into the pressure scale model to calculate the pressure value to be measured.
2. The method according to claim 1, characterized in that, When the sample to be tested is zircon, the indentation model includes: In the formula, The ν3(SiO4) Raman shift of zircon under the target experimental conditions is given. The value represents the ν3(SiO4) Raman displacement of zircon under normal temperature and pressure conditions, where T is the target temperature and P is the pressure to be measured.
3. The method according to claim 1, characterized in that, When the test sample is quartz and the preset peak position is the 464 Raman peak, the pressure standard model includes: In the formula, The displacement of the 464 Raman peak in quartz under the target experimental conditions. The value represents the displacement of the 464 Raman peak of quartz under normal temperature and pressure conditions, where T is the target temperature and P is the pressure to be measured.
4. The method according to claim 1, characterized in that, When the test sample is quartz and the preset peak position is the 206 Raman peak, the pressure standard model includes: In the formula, The displacement of the 206 Raman peak of quartz under the target experimental conditions. The displacement of the 206 Raman peak of quartz under normal temperature and pressure conditions is given by T, where T is the target temperature and P is the pressure to be measured.
5. The method according to claim 1, characterized in that, When the test sample is quartz and the preset peak position is the 128 Raman peak, the pressure standard model includes: In the formula, The displacement of the 128 Raman peak of quartz under the target experimental conditions. The displacement of the 128 Raman peak of quartz under normal temperature and pressure conditions is given by T, where T is the target temperature and P is the pressure to be measured.
6. A pressure calculation system based on Raman spectroscopy, characterized in that, A system for implementing a pressure calculation method based on Raman spectroscopy as described in any one of claims 1-5; the system comprises: a first acquisition module, a second acquisition module, a construction module, and a calculation module; wherein... The first acquisition module is used to acquire the first Raman shift of the test sample relative to a preset peak position in the Raman spectrum of the test sample under target experimental conditions; the test sample includes zircon and quartz; the target experimental conditions include a target temperature value and a test pressure value; The second acquisition module is used to acquire the second Raman shift relative to the preset peak position in the Raman spectrum of the test sample under normal temperature and pressure conditions; The construction module is used to construct a pressure model of the sample to be tested based on the preset peak positions in the Raman spectrum. The calculation module is used to substitute the first Raman displacement, the second Raman displacement, and the target temperature value into the pressure scale model to calculate the pressure value to be measured.
7. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as claimed in any one of claims 1-5.
8. A computer-readable storage medium, characterized in that, The computer-readable storage medium contains program code that can be invoked by a processor to execute the method as described in any one of claims 1 to 5.