Electronic, optical, magnetic, and magnetocaloric properties of double perovskites Sr₂CrOsO₆: first principles approach and Monte Carlo simulation

Employing the Quantum Espresso computational tool and Monte Carlo simulation, we conducted an extensive investigation into the electronic, magnetic, and optical properties of the \({\mathbf{S}\mathbf{r}}_{2}{\mathbf{C}\mathbf{r}\mathbf{O}\mathbf{s}\mathbf{O}}_{6}\) (SCOsO) compound. Our analysis revealed its semiconductor nature with a direct band gap and the presence of spin-down states at the Fermi level. Notably, the Hubbard parameter (U) significantly influenced the magnetic states, illustrating its role in modulating the magnetic moments within the material. The computed exchange interactions using the Ising model unveiled distinct magnitudes for \({\text{Cr}}-{\text{Cr}}\), Os-Os, and Os-Cr interactions, reflecting variations in electronic interactions within the compound. The temperature-dependent magnetization and susceptibility demonstrated a critical temperature of \(634 \, {\text{K}}\), marking a significant ferrimagnetic to paramagnetic phase transition. SCOsO exhibited a significant magnetocaloric properties, displaying substantial values of maximum magnetic entropy change \(\left({\varvec{\Delta}}{{\varvec{S}}}_{{\varvec{M}}}\right)\) and Relative Cooling Power (RCP) under an applied magnetic field of \(2\mathbf{T}\), outperforming various other compounds in this category. Regarding optical properties, our analysis using Quantum Espresso revealed SCOsO's strong reflectivity for green light, indicating its potential for solar light storage. The refractive index displayed distinct variations, suggestive of electronic transitions influenced by the spin–orbit coupling of \(\mathbf{C}\mathbf{r}\) and \(\mathbf{O}\mathbf{s}\) ions within the compound.