Temperature effects on thermodynamic and mechanical properties of the InP, InAs and InSb compounds

The thermodynamic and mechanical properties of the zinc-blende indium pnictides InP, InAs and InSb compounds have been investigated thanks to the statistical moment method in statistical mechanics. We have derived the analytical expressions of thermal induced atomic displacement, lattice constant, elastic moduli (Young's modulus, bulk modulus and shear modulus) and elastic constants of the zinc-blende compounds. The difference of temperature effects on mechanical properties of InSb comparing to InP and InAs compounds has been pointed out. We show that InSb is less affected by temperature while InP changes its mechanical properties from hardness to softness quickly when the temperature increases. The advancement of this method is that it has included the anharmonic effects of thermal lattice vibrations by taking into account the higher-order atomic displacement terms.