Investigation of structural and electronic properties of double perovskites A2LnRuO6 (A = Ba, Ca; Ln = Eu, Dy)

Abstract

Using density functional theory, we investigated the structural, vibrational, and electronic properties of A2LnRuO6 (A = Ba, Ca; Ln = Eu, Dy) double perovskite oxides using GGA and GGA+U exchange-correlation approximations. Ba2LnRuO6 double perovskites exhibit a structure with cubic ( Fm3¯m ) symmetry, whereas Ca2LnRuO6 compounds have monoclinic (P21/n) symmetry. Raman spectroscopy analysis shows stability and the presence of A1g , E g and 2F2g modes for Ba2LnRuO6, while for Ca2LnRuO6, the observed Raman active modes are A g and B g . A2LnRuO6 shows semiconducting nature with an electronic band gap in the range of 1.3 eV-3.27 eV with GGA+U calculations. The spin-polarized calculations indicate the presence of strong magnetic behaviour with magnetic moment equal to 3 μ B /unit cell for Ba2LnRuO6 and 6 μ B /unit cell for Ca2LnRuO6. The spin-up and spin-down states show different band gap values so these compounds can be useful for applications in spintronics and magnetic memory devices.