metal-magnetism-2018-scientifictracks

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I n t e r n a t i o n a l C o n f e r e n c e o n
Metal, Mining and
Magnetic Materials
Journal of Material Sciences
ISSN: 2321-6212
N o v e m b e r 0 1 - 0 2 , 2 0 1 8
P a r i s , F r a n c e
Metal and Magnetism 2018
Page 25
Georges Bouzerar, J Mat. Sci. 2018, Volume:6
DOI: 10.4172/2321-6212-C7-032
The nature of carrier-induced ferromagnetism in both Mn doped III-V
compounds GaAs and InP is investigated. Although, direct band gap and
effective masses are very close in both InP and GaAs, we demonstrate that
the magnetic properties change drastically. The influence of the acceptor
level position on magnetic properties will prove to be crucial. Because of both
dilution effects (percolation) and short-range nature of the carrier induced Mn-
Mn magnetic couplings (calculated), thermal/transverse spin fluctuations and
disorder effects (localization) have to be properly treated (beyond effective
medium or perturbation approach). To tackle this issue efficiently, different
large-scale theoretical approaches are combined: Kernel polynomial method
(KPM) for the accurate calculation of Mn-Mn couplings, Monte Carlo (MC)
and local random phase approximation (L-RPA) for the magnetic properties
(TC, T- dependent magnetization, and magnetic excitation spectrum and spin
stiffness). TC in (In, Mn ) P is found much smaller than that of Mn doped GaAs
and scales linearly with Mn concentration in contrast to the square root behavior
found in (Ga, Mn) As. Moreover, we find that the magnetization behave almost
linearly with the temperature in contrast to the standard mean field Brillouin
shape. These findings are in quantitative agreement with the experimental data
and reveal that magnetic and transport properties are extremely sensitive to the
position of the Mn acceptor level. We finally discuss the transport properties in
both compounds and demonstrate that our non-perturbative theory is able to
capture not only qualitatively but quantitatively as well the transport properties
in these materials such as the infrared optical conductivity, the carrier and Mn
concentration dependent Drude weight, the effects of sample annealing, and
also the metal-insulator-transition as observed experimentally in Mn doped
GaAs, whilst (In-Mn) P remains an insulating compound
Biography
Georges Bouzerar is a Research Director at Centre National de
la Recherche Scientifique (CNRS). He is an expert in quantum
and classical magnetism (itinerant and localized) and in
quantum transport. He has completed his PhD in Mesoscopic
Physics (interplay between electron-electron interaction and
disorder) in 1996 from Paris XI (Orsay) University. He has spent
several years as a Postdoc in Germany (Koeln University, Berlin
University, Max Planck Institute) and in France (Laue Langevin
Institute in Grenoble). He got a Senior Scientist permanent
position at CNRS in 2004 and became research director in
2011. Over the past 10 years he has focused attention on
spintronics, in particular on magnetism and transport in diluted
magnetic semiconductors and non-magnetic impurity induced
ferromagnetism. He has contributed by about 25-30 papers to
this research area and received a prize in 2014 from the French
Academy of Science for his achievements in this field.
Magnetic and transport properties in Mn doped III-V
semiconductor: the cases of GaAs and InP
Georges Bouzerar
CNRS-Université Lyon 1, France