In this work, we study the electronic and magnetic properties of the semiconductor copper (II) oxide doped with three rare earths (RE = Pm, Sm and Er), Cu1_xRExO (x = 0.10) in the rutile structure. The presence of the 4f orbital in our structures imposes us to choose the local density approximation with Self interaction-corrected (LDA-SIC) to improve the results obtained. Depending on the rare earths (RE) used, we discuss for each element the critical temperature extracted by using the mean field approximation (MFA). (C) 2019 Elsevier Ltd. All rights reserved.

The Earth’s core contains, in addition to iron, 5–10

In this work, we carried out an ab-initio study to determine a new material with structural, electronic and magnetic properties that qualifies it as a candidate for use in spintronics. To achieve our goal, we chose copper oxide "CuO " as the host matrix, which is characterized by semiconductor properties, and then doped with three transition metals (Mn, Co and Ni). Our theoretical study of diluted magnetic semiconductors (DMS), (TM = Mn,Co and Ni) doped Copper oxide Cu1-xTmxO, was based on the functional theory of standard density (DFT) using the Korringa-KohnRostoker (KKR) multiple diffusion method as part of the coherent potential approximation (CPA) for the calculation of the electronic structure of materials.In our study as well, we compared the state density (DOS) of each compound using the general gradient approximation (GGA) and the general gradient approximation (GGA) with corrected self-interaction (SIC). The state density spectra of each elements obtained show that CuO doping by transition metals displaces Fermi levels, modifies magnetic properties and changes the nature of our material. Based on these criteria, we will select the material that has the best half-metallic characteristics to be used in spintronics devices. (c) 2019 Elsevier Ltd. All rights reserved.

This study aims to develop a method for calculating stiffness coefficients A and B of the Computer Reconstruction of Automobile Speeds on the Highway (CRASH) algorithm in the case of the frontal impact based on the crash test experiments of the National Highway Traffic Safety Administration (NHTSA). For this purpose, we used two crash reports of Hyundai Sonata GLS 4-Doors Sedan model 2011 to calculate the coefficients A and B accurately and find a relationship between them. Thereafter, to verify the relationship between the coefficients A and B, we selected randomly from NHTSA's database a set of 198 vehicles produced by seven manufacturers between 2003 and 2020 and calculated these coefficients using the computational method suggested in the literature. The crash speeds determined based on these coefficients showed a low correlation with the measured crash speeds obtained during the crash test of the vehicles.However, for the same sample of vehicles, we used the relation found previously to calculate the coefficients A and B, the speeds calculated using these coefficients are perfectly correlated with the impact speeds measured experimentally, we thus conclude that the ratio between the two stiffness coefficients A and B is always equal to 12.512 m regardless of the type of vehicle. This finding will make it possible to simplify the calculation of the energy absorbed in the frontal impacts by the reduction of the two coefficients of stiffness in only one coefficient at the same time as improving the precision of our calculations of kinematic reconstitution.

The thin films Fe doped copper sulphide Cu1−xFexS (CFS) (x = 0.01, 0.03, 0.05, and 0.07) were elaborated by spray pyrolysis deposition technique. The characterization by XRD and SEM of the thin films shows a Covellite CuS single phase without formation of other phases. The structure is a simple hexagonal with unit cell dimension, a = b = 3.79 Å and c = 16.34 Å. The Analysis of the UV–Vis spectra reveals that the energy band gap has been decreased from 2.47 to 1.98 eV with the increase of Fe concentration. The absorption coefficients of CFS films have increased from 1.155 × 105 to 1.712 × 105 cm−1. It has demonstrated that a right band gap with a right band edge alignment at a pH value for Fe-doped CFS can boost the material application as a photocatalyst for the visible light. According to this study, CFS (0.07) thin films for a pH = 3 solutions is a promising material for photocatalysis application for water splitting to hydrogen-oxygen production. Nevertheless, we demonstrate that the formation of straddling gap heterostructure for CuS and CFS for a pH solution between 7 and 8 induces the production of oxygen and hydrogen.

In this paper, we consider the electronic and magnetic proprieties of five rare-earths (RE = Pr, Pm, Sm, Dy, and Tm)-doped Tin (IV) oxide semiconductor Sn1 − xRExO2 (x = 0.10) in the rutile structure. The presence of the 4f orbitals in our structures pushes us to choose the local density approximation with Self-interaction-corrected (LDA-SIC) to improve the obtained results. We also discuss the critical temperature retrieved from the study the total magnetizations and the susceptibilities using Monte Carlo simulations for each rare-earth element used.