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In this paper, a combination of DFT study and Monte Carlo (MC) simulations has been performed on Gd compound which undergoes a second–order phase transition from ferromagnetic state to paramagnetic one. For this single material, the temperature-dependent total magnetization and magnetic susceptibility have been calculated and are revealed that the Curie temperature is acceptable concurrence with the experimental value. Furthermore, it was showed that under an external magnetic field of 2 Tesla (T), MCE of Gd compound around its Curie point in regard to the maximum value of magnetic entropy change ( ), agrees well with the experimental one. Besides, the Relative Cooling Power (RCP) values are found to be 34.37, 69.18, 90.74 and 128 J.kg−1 under different magnetic fields of 0.5, 1.0, 1.5 and 2T, respectively. All findings which are presented here indicate that DFT calculations and Monte Carlo simulations can be efficiently used to predict the magnetic and magnetocaloric features of Gd and related alloys.

Chalcogenide perovskites are prototypical absorber materials based solar cells, they could solve both: the stability and toxicity issues existing in conventional perovskites. A device simulation of BaZrS3 as a potential absorbing material (high chemical stability, direct band gap and a strong light absorption coefficient) based chalcogenide perovskite solar cells is performed by using the one dimensional Solar Cell Capacitance Simulator (SCAPS)-1D software. Parameters like (thickness, doping concentration, defect density of the absorber and interfaces, temperature) are varied in order to inspect their impact on device performance. For this study, a performed architecture has been proposed: FTO (Fluorine doped Tin Oxide)/TiO2 (ETL; Electron Transport Layer)/BaZrS3 (Absorber)/Spiro-OMeTAD (HTL; Hole Transport Layer)/Au (metal back contact). To enhance the solar cell efficiency, an optimization of these key parameters is investigated. Our simulation results in optimized thickness and doping density (NA, ND) of (80 nm; 1×1019 cm-3), (10 nm; 8×1019 cm-3), (850 nm; 1×1020 cm-3) and (60 nm; 9×1019 cm-3) for FTO, TiO2, BaZrS3 and Spiro-OMeTAD materials respectively, with a global illumination spectrum AM1.5 and 440 K as an optimum operation temperature, are found to be: PCE (maximum Power Conversion Efficiency) of 17.29%, FF (fill factor) of 86.26%, Voc (Open Circuit Voltage) of 1.2124 V and Jsc (Short Circuit current density) of 16.5363 mA/cm2.