Theoretical study of structural, electronic and mechanical properties of the ternary polar intermetallic compounds A2MSb (A=Na, K and M=Au, Ag)

Abstract

For the structural, elastic, electronic properties of ternary polar intermetallic compounds (K2AuSb, Na2AuSb, Na2AgSb). We have studied theoretically about these compounds using CASTEP code, which relies on DFT, among many of the approximations for calculate the energy of exchange and correlation, using the GGA-PBESol (GGA) approximation. The results obtained were consistent with the results experimental. The study showed that Na2AgSb and K2AuSb were brittle in nature and Na2Ausb was soft, non-stress resistant, and electronic properties showed that these materials were indirect semiconductors and different values of the energy gap. Mulliken population analysis and distribution the density of the charge a, demonstrated that the bond between the antimony ( Sb) and gold (Au) atoms is low covalent for K2AuSb, Na2Ausb and between the (Sb) antimony and silver atom (Ag) is low ionic bonding for Na2AgSb.