XMCD studies and magnetic properties of ZnTe doped with Ti, Cr, Mn and Co

Using the full potential linear augmented plane wave (FP-LAPW) method as implemented in the WIEN2K code in connection with the Generalized Gradient Approximation (GGA). We study the magnetic properties of ZnTe doped with some transition metals elements. In addition, to the X-ray absorption spectra (XAS) and X-ray Magnetic circular dichroism (XMCD) calculations to compute the orbital and spin moments separately. Two principal examples will be given: The induced magnetic moments ZnTe of the light and heavy 3d elements (Ti, Cr and Mn, Co) can be determined by the XMCD sum rules analysis at the L2,3 edges. Moreover, it has been found that for the lighter 3d elements the spin-orbit splitting of the transitions 2P1/2 and 2P3/2 states reduces toward, which has a consequence that two excitations are coupled

Engineering the magnetic and magnetocaloric properties of PrVO3 epitaxial oxide thin films by strain effects

Combining multiple degrees of freedom in strongly-correlated materials such as transition-metal oxides would lead to fascinating magnetic and magnetocaloric features. Herein, the strain effects are used to markedly tailor the magnetic and magnetocaloric properties of PrVO3 thin films. The selection of appropriate thickness and substrate enables us to dramatically decrease the coercive magnetic field from 2.4 T previously observed in sintered PVO3 bulk to 0.05 T for compressive thin films making from the PrVO3 compound a nearly soft magnet. This is associated with a marked enhancement of the magnetic moment and the magnetocaloric effect that reach unusual maximum values of roughly 4.86 uB and 56.8 J/kg K in the magnetic field change of 6 T applied in the sample plane at the cryogenic temperature range (3 K), respectively. This work strongly suggests that taking advantage of different degrees of freedom and the exploitation of multiple instabilities in a nanoscale regime is a promising strategy for unveiling unexpected phases accompanied by a large magnetocaloric effect in oxides.Comment: This paper is accepted for publication in Applied Physics Letter

Structural, electronic and magnetic properties of LaCr2Si2C: Ab initio calculation, mean field approximation and Monte-Carlo simulation

The magnetic behavior of LaCr2Si2C compound is investigated in this work, using first principle methods, Monte Carlo simulation (MCS) and mean field approximation (MFA). The structural, electronic and magnetic properties are described using ab initio method in the framework of the Generalized Gradient Approximation (GGA), and the Full Potential-Linearized Augmented Plane Wave (FP-LAPW) method implemented in the WIEN2K packages. We have also computed the coupling terms between magnetic atoms which are used in Hamiltonian model. A theoretical study realized by mean field approximation and Monte Carlo Simulation within the Ising model is used to more understand the magnetic properties of this compound. Thereby, our results showed a ferromagnetic ordering of the Cr magnetic moments below the Curie temperature of 30 K (Tc < 30 K) in LaCr2Si2C. Other parameters are also computed as: the magnetization, the energy, the specific heat and the susceptibility. This material shows the small sign of supra-conductivity; and future researches could be focused to enhance the transport and magnetic properties of this system. Keywords: Magnetic properties, Electronic structure, Ab initio, Mean field approximation, Monte Carlo simulation, Superconductivit

Magnetocaloric effect in ternary ErAgAl: Ab initio, mean field and Monte Carlo approaches

ErAgAl has been known as an orthorhombic system of the CeCu2-type with ferromagnetic ground state. In this work, the magnetic and magnetocaloric effect has been studied using first principles calculations, Monte Carlo and Mean Field approaches. The adiabatic temperature change, the isothermal entropy change, and the relative cooling power (RCP) have been calculated. The Erbium magnetic moment calculated by FP-LAPW method is 8.21μB, in good agreement with experimental data. The compound exhibits a second order phase transition from paramagnetic to ferromagnetic state at Tc = 14 K. The isothermal entropy change (-ΔSMmax) reaches a maximum value equal to −12.24 J Kg−1 K−1 for a magnetic field of 6 T showing a large magneto-caloric effect around the Curie temperature with no obvious thermal and magnetic hysteresis loss in good agreement with experimental data. The obtained results make the compound suitable for magnetic refrigeration at low temperature regime. Keywords: Magneto-caloric effect, Relative cooling power, Electronic structure, Monte Carlo simulation, Ferromagnetis

Structural, elastic, electronic and optical properties of RbPbI 3 perovskites studied using ab-initio calculations

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On the origin of the giant magnetocaloric effect in HoMn2O5 single crystals: First principles study and Monte Carlo simulations

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Engineering the magnetocaloric properties of PrVO 3 epitaxial oxide thin films by strain effects

International audienceCombining multiple degrees of freedom in strongly correlated materials such as transition-metal oxides would lead to fascinating magnetic and magnetocaloric features. Herein, the strain effects are used to markedly tailor the magnetic and magnetocaloric properties of PrVO3 thin films. The selection of an appropriate thickness and substrate enables us to dramatically decrease the coercive magnetic field from 2.4 T previously observed in sintered PVO3 bulk to 0.05 T for compressive thin films making from the PrVO3 compound a nearly soft magnet. This is associated with a marked enhancement of the magnetic moment and the magnetocaloric effect that reaches unusual maximum values of roughly 4.86 μB and 56.8 J/kg K with the magnetic field change of 6 T applied in the sample plane in the cryogenic temperature range (3 K), respectively. This work strongly suggests that taking advantage of different degrees of freedom and the exploitation of multiple instabilities in a nanoscale regime is a promising strategy for unveiling unexpected phases accompanied by a large magnetocaloric effect in oxides

Engineering the magnetocaloric properties of PrVO 3 epitaxial oxide thin films by strain effects

International audienc