104 research outputs found
The Ferromagnetic and half metallic behaviors of Fe- and Co- doped SnO2 within Local Density Approximation and Self-Interaction-Corrected
Using ab-initio calculation based on the Korringa-Kohn-Rostoker Coherent Potential Approximation (KKR-CPA) method in connection with the local density approximation without and within self-interaction-corrected (LDA and LDA-SIC), we represent a theoretical study of the SnO2 doped system with transition metals (TM) which are Iron (Fe) and Cobalt (Co). In this system, the stability of the ferromagnetic state compared with the spin-glass state is investigated by comparing their total energies. The Ferromagnetic and half metallic behaviors was observed and conformed with the local-moment-disordered (LMD) state energy for LDA (local density approximation) and LDA-SIC (local density approximation-self-interaction correction) approximation in [Sn0.95TM0.05(Fe or Co)]O2 . Based on mean field method, the Curie temperature is estimated. To explain the origin of magnetic behavior, we give information about total and atom projected density of states functions of Fe and Co elements and we propose a model which describes magnetic interaction in [Sn0.95TM0.05(Fe or Co)]O2
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
Electronic and Magnetic Structures of PrAg bcc Investigated by First Principle and Series Expansions Calculations
International audienc
Electronic Structure and Magnetic Properties of La0.7Ca0.3MnO3 Perovskite
International audienc
Electronic structure of C co-doped (Ga, Fe)N-based diluted magnetic semiconductors
We report results of the study on GaN doped with Fe and co-doped with Carbon
(C), for acceptors defect, making use of the spin-polarized relativistic
Korringa-Kohn-Rostoker coherent-potential approximation method. In order to
understand and to explain the half-metallicity and ferromagnetism stability,
observed in Ga0.95Fe0.05N with acceptor defects, we calculated the
electronic structure and magnetic properties of p-type
Ga0.95Fe0.05N. Furthermore, comparison between the electronic
structure of the substitutional and interstitial carbon in (Ga, Fe)N is also
given. Mechanism of exchange interaction between magnetic ions in
Ga0.95Fe0.05N with acceptor defect is investigated. The hyperfine
interaction has been calculated for the disordered alloy systems
Ga0.95Fe0.05N1-xCx (0.01 ≤ x ≤ 0.08)
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