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

Using density functional theory, we investigated the structural, vibrational, and electronic properties of A 2 LnRuO 6 (A = Ba, Ca; Ln = Eu, Dy) double perovskite oxides using GGA and GGA+ U exchange-correlation approximations. Ba 2 LnRuO 6 double perovskites exhibit a structure with cubic ( <?CDATA Fm3̄m?> Fm 3 ¯ m ) symmetry, whereas Ca 2 LnRuO 6 compounds have monoclinic (P2 1 / n ) symmetry. Raman spectroscopy analysis shows stability and the presence of A 1 g , E g and 2F 2g modes for Ba 2 LnRuO 6 , while for Ca 2 LnRuO 6 , the observed Raman active modes are A g and B g . A 2 LnRuO 6 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 Ba 2 LnRuO 6 and 6 μ B /unit cell for Ca 2 LnRuO 6 . 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.