A first principles based analysis of K2XMoF6 (X = Au, Cs) lead-free double perovskites: exploring their physical properties

Abstract

This study uses first-principles method to analyze the structural, electronic, magnetic, thermoelectric (TE), and optical properties of K2XMoF6 (X = Au, Cs). The modified Becke–Johnson (mBJ) algorithm is applied in the study which provides accurate and thorough information about physical characteristics. The results confirm that K2XMoF6 (X = Au, Cs) are thermodynamically and structurally stable. Electronic characteristics were investigated to determine band gaps (Eg) and state dispersion across bands. The semiconductor behavior of K2CsMoF6 and the half-metallic behavior of K2AuMoF6 were verified using spin-resolved band structure (BS) and density of states (DOS) graphs. K2CsMoF6 has an indirect electronic gap (Eg) of 1.17 eV in spin-up and 5.76 eV during spin-down, while K2AuMoF6 also have indirect Eg of 1.48 eV for spin down and metallic nature in up spin. The entire magnetic moment values for K2AuMoF6 and K2CsMoF6 are 2.99866 µB and 2.9990 µB, respectively, according to magnetic characteristics. For K2AuMoF6 and K2CsMoF6, the greatest optical conductivity values are computed to be at 9.31 and 8.62 eV, respectively. Figure of merit (ZT) value at 300 K temperature is 0.85 for K2AuMoF6 and 0.99 at 450 K for K2CsMoF6 indicating significant efficiency according to TE assessments. According to these findings, both K2AuMoF6 and K2CsMoF6 have promise for usage in TE and optoelectronic applications because of their stability, tunable bandgaps, and encouraging performance.

Keywords Electronic, Magnetic, Thermoelectric Atomic and Molecular Structure and Properties ,Metal-organic Frameworks, Metal Oxides, Perovskites ,Structure and properties of clusters