Impact of Ca2+ doping on Sr2-xCaxCrOsO6 physical behavior (x = 0, 0.5) for energy and spintronic applications

Using ab initio calculations and Monte Carlo simulations, we investigate the electronic, optical, magnetic, and thermodynamic properties of the double perovskites Sr₂CrOsO₆ and Sr_1.5Ca₀.₅CrOsO₆. A strong Cr-O-Os super-exchange interaction and nearly full spin polarization (∼100 %) support the half-metallic behavior of Sr₂CrOsO₆, which has a gap of 0.951 eV in the majority spin channel and a high Curie temperature (T_C) of 724 K.

While maintaining metallic behavior in the minority channel, calcium doping causes a slight increase in the gap to approximately 1.162 eV and a reduction in spin polarization (∼50 %) in the majority channel. This shows a decrease in T_C at 520 K along with a continuation of the semi-metallic character, albeit somewhat diminished. The doped compound is a promising candidate for optoelectronic and thermoelectric applications, as evidenced by optical analysis that shows improved dielectric response, enhanced optical conductivity, and enhanced absorption (up to 54 cm⁻¹ at 3.6 eV). According to these findings, Sr₂CrOsO₆′s multifunctional properties can be efficiently tuned through targeted doping for high-temperature devices, especially those used in energy conversion and spintronics.