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 (Fm3m) symmetry, whereas Ca2LnRuO6 compounds have monoclinic (P21/n) symmetry. Raman spectroscopy analysis shows stability and the presence of A1g, Eg and 2F2g modes for Ba2LnRuO6, while for Ca2LnRuO6, the observed Raman active modes are Ag and Bg. 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 μB/unit cell for Ba2LnRuO6 and 6 μB/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.