Generalized Stacking Fault Energy Calculated from First Principles and Peierls Stress in Magnesium

2002 ◽  
Vol 2002.6 (0) ◽  
pp. 217-218 ◽  
Author(s):  
Tokuteru UESUGI ◽  
Masanori KOHYAMA ◽  
MASAHIDE Kohzu ◽  
Kenji HIGASHI
Keyword(s):  
First Principles ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Peierls Stress ◽  
Generalized Stacking Fault ◽  
Generalized Stacking Fault Energy

scholarly journals First-Principles Study on the Elastic Constants and Structural and Mechanical Properties of 30° Partial Dislocation in GaAs

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Huili Zhang ◽  
Qiannan Gao ◽  
Defang Lu ◽  
Yunchang Fu ◽  
Lumei Tong
Keyword(s):  
Elastic Constants ◽  
Structural Relaxation ◽  
First Principles ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Peierls Stress ◽  
Experimental Result ◽  
Third Order ◽  
Generalized Stacking Fault ◽  
Generalized Stacking Fault Energy

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.

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