Abstract
The second‐order elastic constants, third‐order elastic constants, and the generalized‐stacking‐fault energy for semiconductor GaAs are investigated using the first‐principles calculations. The predictions of elastic constants are obtained from the coefficients of the fitted polynomials of the energy‐strain functions. It is found that the nonlinear elastic effects must be considered when the applied deformations are larger than approximately 1.5%. With the Lagrangian strains up to 6.4%, the terms included up to third order in energy expansion functions are sufficient. The elastic constants given in this work agree well with the previous results and experimental data except for C144. C144 given by the present paper is a positive value, and the estimated 3 GPa agrees well with the experimental result of 2 GPa. The research results can provide a reference for understanding the elasticity of GaAs. The generalized‐stacking‐fault energy has been calculated without and with structural relaxation, respectively. The unstable stacking fault energy with structural relaxation is about two‐thirds of that without relaxation. The dislocation width and Peierls stress for 30° partial in GaAs have been investigated based on the improved P‐N theory. The dislocation width is very narrow (only about one‐fifth of Burgers vector b), which is reasonable for covalent materials. The Peierls stress is about 4 GPa, in good agreement with the experimental result of 2∼3 GPa.
Highlights
III–V semiconductors receive the widespread attention due to the latent application prospect, such as photo-detectors, lasers, and light-emitting diodes [1,2,3,4,5]
One can see that when the applied deformations are larger than approximately 1.5%, the linear elasticity is not sufficient and the third-order effects must be considered. e calculated results for lattice constant and elastic constants are presented in Table 2. e results are all agreeing well with the previous results and experimental data except for C144. e third-order elastic constants (TOECs) C144 given by the present paper is a positive value, and the estimated value of 3 GPa agrees well with the experimental result of 2 GPa given in [14]. e results given by the present paper can provide a reference for understanding the elasticity of GaAs
The secondorder elastic constants (SOECs), TOECs, and generalized-stacking-fault energy (GSFE) for semiconductor GaAs are investigated using the first-principles total-energy calculations. e predictions of SOECs and TOECs are obtained from the coefficients of the fitted polynomials of the energy-strain functions
Summary
First-Principles Study on the Elastic Constants and Structural and Mechanical Properties of 30° Partial Dislocation in GaAs. e second-order elastic constants, third-order elastic constants, and the generalized-stacking-fault energy for semiconductor GaAs are investigated using the first-principles calculations. E elastic constants given in this work agree well with the previous results and experimental data except for C144. C144 given by the present paper is a positive value, and the estimated 3 GPa agrees well with the experimental result of 2 GPa. e research results can provide a reference for understanding the elasticity of GaAs. e generalized-stacking-fault energy has been calculated without and with structural relaxation, respectively. E dislocation width and Peierls stress for 30° partial in GaAs have been investigated based on the improved P-N theory. C144 given by the present paper is a positive value, and the estimated 3 GPa agrees well with the experimental result of 2 GPa. e research results can provide a reference for understanding the elasticity of GaAs. e generalized-stacking-fault energy has been calculated without and with structural relaxation, respectively. e unstable stacking fault energy with structural relaxation is about two-thirds of that without relaxation. e dislocation width and Peierls stress for 30° partial in GaAs have been investigated based on the improved P-N theory. e dislocation width is very narrow (only about onefifth of Burgers vector b), which is reasonable for covalent materials. e Peierls stress is about 4 GPa, in good agreement with the experimental result of 2∼3 GPa
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