Electronic and Mechanical Properties of High-Spin-Polarized Perovskite Compounds Cs2XYF6 (X = K, Ti and Tl, Y=Fe and V).

The mechanical and electronic properties of perovskite compounds Cs₂KFeF₆, Cs₂KVF₆, Cs₂TiVF₆ and Cs₂TlVF₆ were comprehensively studied. It was found that the four compounds have 100% spin polarizability in the equilibrium state, Cs₂KFeF₆ exhibits bipolar magnetic semiconductor with a band gap of 1.72 eV, and Cs₂KVF₆, Cs₂TiVF₆ and Cs₂TlVF₆ show half-metallic properties with half-metallic gap of 1.75 eV, 0.94 eV and 1.76 eV, respectively. All four compounds show mechanical stability and varying degrees of anisotropy, and calculations of the ideal tensile strength show that they resist well in one direction at different strains. It is found that Cs₂KFeF₆ exhibits stable semiconductor characteristics under strain and strong light absorption in visible region under tensile strain. Cs₂KVF₆, Cs₂TiVF₆ and Cs₂TlVF₆ maintain robust half-metallic properties throughout the strain interval. The total magnetic moments of the equilibrium and strains are always kept at integer values, and the transition metal atoms contribute the most to the total magnetic moments. The high spin polarizability, modulable visible light absorption and wider half-metallic gap of these four perovskite compounds indicate that have demonstrated significant potential and wide-ranging application prospects in the exploration of next-generation optoelectronic devices and spintronics. [ABSTRACT FROM AUTHOR]