Exploring the structural, electronic, magnetic, and magneto-optical properties of double perovskites Ca_2TMIrO_6 (TM = Fe, Co) through first principles study

Abstract

This study is aimed at exploring the electronic, magnetic, and magneto-optical properties of double perovskites Ca_2FeIrO_6 and Ca_2CoIrO_6 with monoclinic structure (space group P21/c) in order to examine their potential applications in spintronic and photovoltaic devices. The calculations were done using the full-potential linearized augmented plane wave within the density functional theory. For the electronic exchange-correlation function, we used the generalized gradient approximation (GGA) and GGA+U (Hubbard potential), and spin-orbit coupling (SOC). The study showed that Ca_2FeIrO_6 and Ca_2CoIrO_6 exhibit a monoclinic structure (space group P21/c). The structure relaxation shows an antiferromagnetic behavior in both systems with a magnetic moment of about 6.00 μB for Ca_2FeIrO_6 and 4.00 μB for Ca_2CoIrO_6 by using GGA+U approximation. The results of GGA and GGA+U predict the half-metallic behavior of Ca_2FeIrO_6 and Ca_2CoIrO_6. The magneto-optical polar Kerr effect (MOKE) was examined by studying the variation of Kerr and ellipticity rotation. The Kerr rotation angle is 1.3º at 4.82 eV and -1.21º at 4.3 eV, and the ellipticity angle is -1.21º at 4.3 eV for Ca_2FeIrO_6. In the case of Ca_2CoIrO_6, the Kerr rotation angle is -1.04º at 4.05 eV; the significant Kerr rotation in both compounds may suggest the application of these materials in optoelectronics bias. The named compounds have a potential application in the field of spintronics and its devices, such as in optoelectronics technologies.

Keywords

• double perovskites
• kerr effect
• optical properties
• wien2k