A high-throughput screening method for novel layered perovskite materials with high damage tolerance

Abstract

The present invention relates to the field of structural ceramics, and specifically to a high-throughput screening method for novel layered perovskite materials with high damage tolerance. The method comprises: S1, determining the space group and composition range of the material, automatically searching the crystallographic public database, and obtaining a structure file that meets the requirements; S2, calculating and obtaining the elastic constant c ij , and the band gap E g High-throughput calculation; after cell expansion, calculate the interatomic force constants of all materials; S3, screen materials; S4, analyze the anisotropy of materials and define the thermal conductivity anisotropy index A κ =κ x / κ z The present invention uses a high-throughput computational method to quickly grasp the mechanical properties of layered materials and obtain materials that meet the requirements based on mechanical stability and damage tolerance criteria. It can also reveal the anisotropic properties of layered materials, reducing the time and resource consumption required by traditional trial-and-error methods.

Description

Technical Field

[0001] The present invention relates to the field of structural ceramics, and in particular to a high-throughput screening method for a novel layered perovskite material with high damage tolerance. Background Art

[0002] The continuous development of the aerospace field has placed higher demands on the heat resistance of the hot-end components of aerospace vehicles. Many ceramic materials, including simple perovskite oxides, are widely used due to their excellent high-temperature performance. However, their inherent properties such as brittleness, low damage tolerance, and crack sensitivity make them prone to strength failure at high temperatures, becoming a major challenge in their engineering application. Therefore, it is urgent to discover high-temperature ceramic materials with high toughness and high damage tolerance. The high damage tolerance ceramics that have been widely studied currently have a structural feature of alternating strong and weak chemical bonds. The weak bonding relationship between atoms plays an important role in the toughening mechanism of ceramic materials.

[0003] Layered perovskite, as a derivative material system of simple perovskite, is generally composed of perovskite units and other layered units stacked along a specific direction, and the layers are connected by relatively weak covalent bonds or van der Waals forces. This unique crystal structure and bonding relationship gives it the excellent high-temperature stability and rich elemental composition of simple perovskite, while also having great potential for high damage tolerance and high fracture toughness.

[0004] However, to date, research on layered perovskites has primarily focused on individual materials or systems, with less attention paid to their mechanical properties, resulting in a lack of a comprehensive understanding of their properties. Traditional experimental "trial and error" research methods are time-consuming, inefficient, costly, and limited in scope. Summary of the Invention

[0005] The purpose of the present invention is to address the problems existing in the background technology and propose a new high-throughput screening method for layered perovskite materials with high damage tolerance. The mechanical properties of layered materials can be quickly mastered through high-throughput calculation methods, and materials that meet the requirements can be obtained based on mechanical stability and damage tolerance criteria. At the same time, it can reveal the anisotropic properties of layered materials and reduce the time and resource consumption required by traditional trial-and-error methods.

[0006] The technical solution of the present invention is a high-throughput screening method for a novel high-damage-tolerant layered perovskite material, comprising:

[0007] S1. Determine the space group and composition range of the material, and automatically search the public crystallographic database to obtain a structure file that meets the requirements. For example, you can search the International Crystallographic Database to obtain initial structural data.

[0008] S2. Calculate and obtain various performance parameters, including the following steps S21-S24:

[0009] S21. Optimize the structure of all materials to obtain a stable crystal structure;

[0010] S22, calculated elastic constant c of the steady-state structure ij , where i, j = 1 to 6;

[0011] S23, using hybrid functional HSE06 to calculate band gap E g High-throughput computing;

[0012] S24. After cell expansion, calculate the interatomic force constants of all materials;

[0013] S3, screening materials, including the following steps S31-S33:

[0014] S31. Screening structural stability materials, using the Born-Huang stability criterion, when the material meets the conditions: c 11 >|c 12 |, 2c 13 c 13 <c 33 (c 11 +c 12 ), c 44 >0,c 66 When it is greater than 0, it is considered to have good mechanical stability; screen the materials with dynamic stability and screen the materials with no imaginary frequency in the phonon spectrum according to the interatomic force constant results;

[0015] S32. Further calculate the elastic modulus and Pugh's ratio G / B based on the data in S2, where G is the shear modulus and B is the bulk modulus. Use G / B < 0.571 to screen high damage tolerance materials.

[0016] S33, using band gap E g >1eV removes materials with high electronic thermal conductivity to obtain high damage tolerance perovskite materials with lower thermal conductivity suitable for high temperature environments;

[0017] S4. Analyzing the anisotropy of the material, including the following steps S41-S42:

[0018] S41. Calculate the tensile strength and shear strength of the material in different directions, obtain the mechanical anisotropy of the material, and define the tensile strength anisotropy index A. T =σ

[100] / σ

[001] ;

[0019] S42. Solve the linear Boltzmann equation and predict the thermal conductivity κ in different directions x and κ z , knowing the thermal anisotropy of the material, defining the thermal conductivity anisotropy index Aκ =κ x / κ z .

[0020] Preferably, in step S22, six strain steps are applied to the material, and the second-order elastic constant c of the material is obtained by fitting the stress-strain curve. ij , where i, j = 1 to 6, and the maximum strain is 0.6%.

[0021] Preferably, in step S2, the calculation is performed using a first-principles calculation software package, using GGA-PBEsol to describe the exchange-correlation functional, with a cutoff energy of 500 eV and a k-point density set to less than The energy and force convergence indices are and 10 -6 eV / atom, GGA (Generalized Gradient Approximation) is an approximation method in density functional theory. PBEsol functional is a calculation method used in density functional theory (DFT). It is a type of generalized gradient approximation (GGA) specifically designed to describe the electronic structure and properties in solid materials.

[0022] Preferably, in step S24, the interatomic force constants of the material are calculated using the Phonopy software package to obtain the phonon spectrum. Phonopy is an open source software package for calculating phonon modes and phonon density.

[0023] Preferably, in step S3, the shear modulus G, the bulk modulus B and the Pugh's ratio G / B are obtained by the Voigt-Reuss-Hill approximation. The Voigt-Reuss-Hill approximation is a method for estimating the elastic modulus of a material, especially in first-principles calculations. This method is based on two extreme assumptions about the elastic behavior of the material, namely the Voigt assumption and the Reuss assumption, and obtains a more accurate estimate by taking the average of the two.

[0024] Preferably, in step S41, uniaxial tensile strain is applied in the

[100] and

[001] directions, and shear strain is applied in the (100)

[010] and (001)

[010] directions to calculate the theoretical strength, and the lattice vector is gradually deformed in the direction of the applied strain, and the structure is relaxed at each step until the stress generated by the applied strain disappears.

[0025] Preferably, in step S42, the third-order force constant is calculated after cell expansion, and the linear Boltzmann equation is solved using the ShengBTE software package. The ShengBTE software package is a software tool for simulating and understanding phonon transport in solids. It is based on the Boltzmann equation of motion and is specifically used to calculate and analyze the phonon scattering and thermal conductivity of materials.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] 1. The present invention adopts the first-principles calculation method, which predicts the mechanical properties of materials based solely on the crystal structure of the material and the basic laws of physics. It does not require experimental operation, has a simple process and is easy to implement, with a short cycle time, high efficiency and low cost.

[0028] 2. This invention obtains the mechanical properties of layered materials through batch calculations, significantly improving the efficiency of material screening and reducing the time and resource consumption required by traditional trial-and-error methods. Taking into account their stability and damage tolerance properties, it accelerates the discovery and development of layered high-damage-tolerance perovskite materials.

[0029] 3. The present invention further studies the anisotropy of high damage tolerance perovskite materials, providing theoretical guidance for the orientation of crystal or coating growth in experiments, which helps to discover potential layered high damage tolerance materials and prepare materials with better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A system structure block diagram of an embodiment of the present invention;

[0031] Figure 2 is a flow chart of a method according to an embodiment of the present invention;

[0032] Figure 3 The theoretical intensity diagram of Ruddlesden–Popper type perovskite;

[0033] Figure 4 Anisotropy diagram of the thermal conductivity of Ruddlesden–Popper perovskite. DETAILED DESCRIPTION

[0034] like Figure 1-Figure 4 As shown, this embodiment proposes a new high-throughput screening method for layered perovskite materials with high damage tolerance, including:

[0035] S1. Establishing the initial structure acquisition module: Identifying a Ruddlesden–Popper (RP) type layered perovskite (ABX3) n The space group of (A'X)(n=1, 2, 3) is I4 / mmm, and the composition range is alkaline earth metals, transition metals, rare earth elements, and oxygen. Automatic searches in public databases such as the International Crystallographic Database yielded 64 RP perovskite structure files that meet the requirements;

[0036] S2. Establish a high-throughput computing module, set input files and computing parameters, including the following steps S21-S24:

[0037] S21. Structural optimization of material 64 was performed to obtain the steady-state crystal structure. The theoretical lattice parameters were compared with the experimental values, and the maximum error was 1.01%, confirming the accuracy of the calculation.

[0038] The above calculations were performed using the VASP (Vienna Ab-initio Simulation Package) software package based on density functional theory. GGA-PBEsol was used to describe the exchange-correlation functional, with a cutoff energy of 500 eV and a k-point density of less than The energy and force convergence criteria are and 10 -6 eV / atom;

[0039] S22. Calculate the elastic constant c by applying six strain steps ij (i, j = 1 to 6), the maximum strain is 0.6%, and the elastic constant c of the calculated steady-state structure ij (i, j = 1 to 6);

[0040] S23, using hybrid functional HSE06 to calculate band gap E g High-throughput computing;

[0041] S24. Use Phonopy to construct a 3×3×1 supercell and calculate its interatomic force constants to obtain the phonon spectrum.

[0042] S3. Establishing a performance screening module to screen materials, including the following steps S31-S33:

[0043] S31, screening structural stability materials, using the Born-Huang stability criterion, when the material meets the conditions: c 11 >|c 12 |, 2c 13 c 13 <c 33 (c 11 +c 12 ), c 44 >0,c 66 When it is greater than 0, it can be considered to have good mechanical stability; screen the materials with dynamic stability and screen the materials with no imaginary frequency in the phonon spectrum according to the interatomic force constant results;

[0044] S32. Based on the data of S2, the Voigt-Reuss-Hill approximation is used to further calculate the elastic modulus and Pugh's ratio G / B, and G / B < 0.571 is used to screen high damage tolerance materials;

[0045] S33, perovskite oxide itself has low lattice thermal conductivity, using the band gap E g>1eV removes materials with high electronic thermal conductivity, and finally obtains five high damage tolerance RP perovskite materials suitable for high temperature environments, see Table 1;

[0046] Table 1. Five new high damage tolerance Ruddlesden–Popper perovskite materials screened

[0047]

[0048] S4. Establish an anisotropy analysis module to analyze the anisotropy of the material according to the structural characteristics of the layered material, including the following steps S41-S42:

[0049] S41. Calculate the tensile strength σ in the

[100] and

[001] directions and the shear strength τ in the (100)

[010] and (001)

[010] directions. Due to the weak interlayer chemical bonds, the tensile strength in the z direction is lower and the shear strength in the (001) plane is lower. Define the tensile strength anisotropy index A. T =σ

[100] / σ

[001] ;

[0050] S42. Use the ShengBTE software package to solve the linear Boltzmann equation to predict the thermal conductivity κ in different directions x and κ z The layered structure blocks the heat conduction in the z direction, resulting in a lower κ z , define the thermal conductivity anisotropy index A κ =κ x / κ z .

[0051] This example uses high-throughput simulations to determine the mechanical properties of layered materials and establishes screening criteria for identifying high-damage-tolerant ceramic materials. Based on first-principles calculations, this example uses a custom space group and elemental composition range for layered perovskite materials, automatically retrieving and acquiring the material's crystal structure from public databases such as the International Crystallographic Database. High-throughput computational methods are then used to relax all crystal structures, further determining performance parameters such as the HSE06 band gap, elastic constant, elastic modulus, Pugh's ratio G / B, and interatomic force constant for all materials. Phonon spectra and the Born-Huang stability criterion are used to screen for structurally stable materials, while damage tolerance criteria are used to screen for highly damage-tolerant materials. Further investigation of the anisotropy of mechanical and thermal properties caused by the layered structure will help identify potential layered materials with high damage tolerance and provide guidance for the orientation of crystal and coating growth in experiments.

[0052] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A high-throughput screening method for a novel layered perovskite material with high damage tolerance, characterized in that: include: S1. Determine the space group and composition range of the material, perform automatic search in the crystallographic public database, and obtain the required structure file; S2. Calculate and obtain various performance parameters, including the following steps S21-S24: S21. Optimize the structure of all materials to obtain a stable crystal structure; S22, calculated elastic constant c of the steady-state structure ij , where i, j = 1~6; S23, using hybrid functional HSE06 to calculate band gap E g High-throughput computing; S24. After cell expansion, calculate the interatomic force constants of all materials; S3, screening materials, including the following steps S31-S33: S31, screening structural stability materials, using the Born-Huang stability criterion, when the material meets the conditions: c 11 >|c 12 |, 2c 13· c 13 <c 33 (c 11 +c 12 ), c 44 >0,c 66 When it is greater than 0, it is considered to have good mechanical stability; screen the materials with dynamic stability and screen the materials with no imaginary frequency in the phonon spectrum according to the interatomic force constant results; S32. Further calculate the elastic modulus and Pugh's ratio G / B based on the data of S2, and use G / B < 0.571 to screen high damage tolerance materials; S33, using band gap E g >1 eV removes materials with high electronic thermal conductivity to obtain high damage tolerance perovskite materials with lower thermal conductivity suitable for high temperature environments; S4. Analyzing the anisotropy of the material, including the following steps S41-S42: S41. Calculate the tensile strength and shear strength of the material in different directions, obtain the mechanical anisotropy of the material, and define the tensile strength anisotropy index A. T =σ [1 0 0] / σ [0 0 1] ,σ [1 0 0] is the tensile strength in the [1 0 0] direction, σ [0 0 1] is the tensile strength in the [0 0 1] direction; S42. Solve the linear Boltzmann equation and predict the thermal conductivity κ in different directions x and κ z , knowing the thermal anisotropy of the material, defining the thermal conductivity anisotropy index A κ =κ x / κ z .

2. The high-throughput screening method for a novel high damage tolerance layered perovskite material according to claim 1, characterized in that: In step S22, six strain steps are applied to the material, and the second-order elastic constant c of the material is obtained by fitting the stress-strain curve. ij , where i, j = 1~6 and the maximum strain is 0.6%.

3. The high-throughput screening method for a novel high damage tolerance layered perovskite material according to claim 2, characterized in that: In step S2, the first-principles calculation software package was used to perform the calculations. GGA-PBEsol was used to describe the exchange-correlation functional, with a cutoff energy of 500 eV, a k-point density of less than 0.05 / Å, and energy and force convergence scales of 10, respectively. -3 eV / Å and 10 -6 eV / atom.

4. The high-throughput screening method for a novel layered perovskite material with high damage tolerance according to claim 3, characterized in that: In step S24, the interatomic force constants of the material are calculated using the Phonopy software package to obtain the phonon spectrum.

5. The high-throughput screening method for a novel layered perovskite material with high damage tolerance according to claim 1, characterized in that: In step S3 , the shear modulus G, bulk modulus B, and Pugh's ratio G / B are obtained by the Voigt-Reuss-Hill approximation.

6. The high-throughput screening method for a novel high damage tolerance layered perovskite material according to claim 1, characterized in that: In step S41, uniaxial tensile strain is applied in the directions of [1 0 0] and [0 0 1], and shear strain is applied in the directions of (1 0 0)[0 1 0] and (0 01)[0 1 0] to calculate the theoretical strength. The lattice vector is gradually deformed in the direction of the applied strain, and the structure is relaxed at each step until the stress generated by the applied strain disappears.

7. The high-throughput screening method for a novel high damage tolerance layered perovskite material according to claim 6, characterized in that: In step S42, the third-order force constant is calculated after cell expansion, and the linear Boltzmann equation is solved using the ShengBTE software package.

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