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Using density functional theory calculations within the generalized gradient approximation, the electronic density of states and band structure of NdMnO 3 simple perovskite are analyzed. It is found that the compound behaves as a ferromagnetic half-metal material. By using Monte Carlo simulations within the framework of the Ising model, the effects of the crystal field and the exchange interaction between the magnetic atoms Mn–Mn and Nd–Mn on the magnetization, susceptibility, specific heat, and internal energy are investigated. The magnetocaloric effect of NdMnO 3 is also examined. It is observed that the relative cooling power (RCP) increases when the applied magnetic field or Mn–Mn exchange interaction is increased, whereas the RCP decreases when the crystal field or Nd–Mn exchange interaction is increased. These results show that NdMnO 3 is a potential candidate for use in magnetic refrigeration and spintronic applications. [ABSTRACT FROM AUTHOR]

Based on the density functional theory and the Monte Carlo Simulation (MCS), the structural, the electronic and the magnetic properties of Sr 2 TiMoO 6 double perovskite have been studied with (GGA), (GGA + U) and (GGA + U + SOC) approaches. The lattice parameter, the band structure and the electronic densities of states have been analyzed. Furthermore, the results show a half-metallic behavior of the compound with (GGA + U) . By the energy calculation, Sr 2 TiMoO 6 oxide shows an antiferromagnetic ordering. The exchange coupling of Sr 2 TiMoO 6 has been also computed in order to investigate the magnetic properties by using MCS in the framework of the Ising model. Interesting phenomena have been obtained such as the first-order transitions and multiple hysteresis loops. These results make Sr 2 TiMoO 6 a promising candidate for spintronic applications. [ABSTRACT FROM AUTHOR]

Based on the density functional theory and the Monte Carlo Simulation (MCS), the structural, the electronic and the magnetic properties of Sr 2 TiMoO 6 double perovskite have been studied with (GGA), (GGA + U) and (GGA + U + SOC) approaches. The lattice parameter, the band structure and the electronic densities of states have been analyzed. Furthermore, the results show a half-metallic behavior of the compound with (GGA + U) . By the energy calculation, Sr 2 TiMoO 6 oxide shows an antiferromagnetic ordering. The exchange coupling of Sr 2 TiMoO 6 has been also computed in order to investigate the magnetic properties by using MCS in the framework of the Ising model. Interesting phenomena have been obtained such as the first-order transitions and multiple hysteresis loops. These results make Sr 2 TiMoO 6 a promising candidate for spintronic applications. [ABSTRACT FROM AUTHOR]

The conception and modeling of a photovoltaic cell are done by combining the density functional theory (DFT) and solar cell capacitance simulator (SCAPS). The search for new lead-free halide semiconductor perovskite materials with an appropriate band gap, which can be used as good absorbers of solar radiation in the studied photovoltaic cell, is realized by substituting a percentage of sodium (Na) with potassium (K) and sulphur (S) in the double perovskite Cs 2 NaCrCl 6. The study also focuses on the choice of the best materials for the electron transport layer (ETL) and the hole transport one (HTL) as well as the thickness of the perovskite semiconductor materials Cs 2 Na 1− x X x CrCl 6 (X = S and K). The results reveal that Cu 2 O and WS 2 are suitable materials for HTL and ETL layers, respectively. The optimal thickness of the perovskite semiconductor is equal to 2 μm. Under optimized conditions, the photovoltaic device power conversion efficiency (η) equals 15.01 % and 20.01 % by using Cs 2 Na 0.5 K 0.5 CrCl 6 with E g = 1.8 eV and Cs 2 NaCrCl 6 with E g = 1.6 eV as active layer, respectively. Therefore, the obtained photovoltaic cell model is (Cu 2 O / Cs 2 NaCrCl 6 / WS 2 /FTO), with an efficiency of η = 20.01 %. • New semiconductor perovskite Cs 2 Na 1− x X x CrCl 6 (X = S and K) with appropriate band gap have been found. • Studies of ETL, HTL and semiconductor perovskite thickness have been done. • The efficiency of designed photovoltaic cell (Cu 2 O ∕ Cs 2 NaCrCl 6 ∕ WS 2 ∕FTO) is η = 20.01 %. • Conception and modeling of photovoltaic cell is done by combining DFT and SCAPS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bi 2 NiCrO 6 is synthesized by the sol–gel method. • Bi 2 NiCrO 6 shows a cubic structure with an Fm3m space group. • Bi 2 NiCrO 6 is a metallic and ferromagnetic material (μ=1.17μB). • Bi 2 NiCrO 6 is a good candidate for spintronic application. In this work, the experimental and theoretical studies of Bi 2 NiCrO 6 double perovskite material have been performed. The synthesis of Bi 2 NiCrO 6 is made by sol–gel method. The X-ray diffraction (XRD) characterisation of the material reveals that the double perovskite adopts a cubic structure (a = 7.75 Å) with Fm3m space group. Based on the Density Functional Theory (DFT) with spin polarized calculations, the electronic and magnetic properties have been investigated. From the total electronic density of states and the electronic band structure analysis, it is found that Bi 2 NiCrO 6 exhibits a metallic behavior. It is also found that the studied compound is ferromagnetic material with a total magnetic moment 1.17 μ B . The results show that Bi 2 NiCrO 6 material is a good candidate for using in devices that requires multifunctional operations including spintronic. [ABSTRACT FROM AUTHOR]

[Display omitted] • DFT has been used to study the optic and electronic properties of Cs 2 AgBiX 6 (X = I ; Br ; Cl and F). • The studied compounds exhibit a semiconductor behavior. • The fluorine based perovskite is the least absorbent. • Bromine and Chlorine based perovskites are very interesting for the photovoltaic and optoelectronic. Lead free halide double perovskites are widely studied for their semiconducting behavior which allows them to be used as absorbing materials in solar cells and optoelectronic applications. In this paper, in order to look for perovskite materials with appropriate absorption and band gap, our aim is to study the electronic and optical properties of Cs 2 AgBiX 6 (X = I , Br , Cl and F) by using the density functional theory (DFT) with generalized gradient approximation (GGA). The found results show that the investigated halide compounds present a semiconductor features which absorb in a long wavelength range. Furthermore, iodine based halide perovskite exhibits a negative values of the dielectric function real part which correspond to a high photon reflection, besides the fluorine one is the least absorbent material. From the obtained results, our work confirm that, bromine and chlorine based double perovskites are very interesting for the photovoltaic and optoelectronic applications. [ABSTRACT FROM AUTHOR]