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Related papers: \textit{Additional} carrier-mediated ferromagnetis…

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In numerous diluted magnetic semiconductor (DMS) systems, the competition takes place between the short-range antiferromagnetic (AF) superexchange interactions and the long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling mediated by the…

Materials Science · Physics 2016-10-04 K. Szalowski

Indirect exchange coupling in magnetic multilayers, also known as the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, is known to be highly effective in controlling the interlayer alignment of the magnetization. This coupling is typically…

A lattice spin-fermion model for diluted magnetic semiconductors (DMS) is investigated numerically, improving on previously used mean-field (MF) approximations. Curie temperatures are obtained varying the Mn-spin x and hole n densities, and…

Strongly Correlated Electrons · Physics 2009-11-07 Gonzalo Alvarez , Matthias Mayr , Elbio Dagotto

We investigate the influence of degeneracies of the conduction band and the $f$-orbital on the stability of ferromagnetism in the periodic Anderson model. To this end we calculate the temperature dependence of the inverse susceptibility for…

Strongly Correlated Electrons · Physics 2009-11-13 Unjong Yu , Krzysztof Byczuk , Dieter Vollhardt

The magnetic properties of dilute magnetic semiconductors (DMS) are calculated from first-principles by mapping the ab initio results on a classical Heisenberg model. It is found that the range of the exchange interaction in (Ga, Mn)N is…

Materials Science · Physics 2007-05-23 K. Sato , W. Schweika , P. H. Dederichs , H. Katayama-Yoshida

We use the local density approximation (LDA) and LDA+U schemes to study the magnetism of (GaMn)As and (GaMn)N for a number of Mn concentrations and varying number of holes. We show that for both systems and both calculational schemes the…

Materials Science · Physics 2009-11-10 L. M. Sandratskii , P. Bruno , J. Kudrnovský

We study the interatomic exchange interactions and Curie temperatures in half-metallic semi Heusler compounds NiCrZ (Z=P, Se, Te) and NiVAs. The study is performed within the framework of density functional theory. The calculation of…

Materials Science · Physics 2015-06-25 E. Sasioglu , L. M. Sandratskii , P. Bruno

A detailed study of the paramagnetic to ferromagnetic phase transition in the one-band Hubbard model in the presence of binary alloy disorder is presented. The influence of the disorder (with concentration $x$ and $1-x$ of the two alloy…

Strongly Correlated Electrons · Physics 2009-11-07 Krzysztof Byczuk , Martin Ulmke , Dieter Vollhardt

Employing first-principles electronic structure calculations in conjunction with the frozen-magnon method we study the effective exchange interactions and spin waves in local moment ferromagnets. As prototypes we have chosen three…

Materials Science · Physics 2012-10-30 I. Galanakis , E. Sasioglu

Magnetism of the spin-$\frac12$ $\alpha$-KVOPO$_4$ is studied by thermodynamic measurements, $^{31}$P nuclear magnetic resonance (NMR), neutron diffraction, and density-functional band-structure calculations. Ferromagnetic Curie-Weiss…

We present a semi-analytic theory for the Curie temperature in diluted magnetic semi-conductors that treats disorder effects exactly in the effective Heisenberg Hamiltonian, and spin fluctuations within a local RPA. The exchange couplings…

Disordered Systems and Neural Networks · Physics 2015-06-24 Georges Bouzerar , Timothy Ziman , Josef Kudrnovsky

We propose an explanation of the anomalous growth of plasticity in ferromagnets near the Curie point. We demonstrate that this effect is caused by spin-dependent detachment of dislocations from obstacles under an influence of the internal…

Materials Science · Physics 2009-11-07 M. Molotskii , V. Fleurov

Magnetic two-dimensional materials have potential application in next-generation electronic devices and have stimulated extensive interest in condensed matter physics and material fields. However, how to realize high-temperature…

Materials Science · Physics 2024-06-19 Panjun Feng , Shuo Zhang , Dapeng Liu , Miao Gao , Fengjie Ma , Xun-Wang Yan , Z. Y. Xie

In this pedagogical paper, the comparative analysis of two common approaches describing the ferromagnetic phase transition in diluted magnetic semiconductors (DMS) is expounded in terms of Weiss field approximation. Assuming a finite spin…

Materials Science · Physics 2021-07-20 Y. G. Semenov , S. M. Ryabchenko

The temperature dependence of magnetization and specific heat of the ferromagnetic compound DyFe2Zn20 has been measured in detail in various magnetic fields. We have observed anomalous magnetic behavior, i.e., a strong anisotropy at 2 K,…

We study whether Fermi-surface (FS) nesting can give rise to high-temperature superconductivity in iron pnictides. Starting with ab initio construction of an effective four-orbital model, we employ the fluctuation-exchange approximation to…

Superconductivity · Physics 2015-05-14 Ryotaro Arita , Hiroaki Ikeda

The metal-graphene contact resistance is one of the major limiting factors toward the technological exploitation of graphene in electronic devices and sensors. A high contact resistance can be detrimental to device performance and spoil the…

In the present work ferromagnetic ordering in the Hubbard model generalized by taking into account the inter-atomic exchange interaction and correlated hopping in partially filled narrow band is considered. Expressions for the magnetization…

Condensed Matter · Physics 2007-05-23 L. Didukh

The electronic properties, exchange interactions, finite-temperature magnetism, and transport properties of random quaternary Heusler Ni$_{2}$MnSn alloys doped with Cu- and Pd-atoms are studied theoretically by means of {\it ab initio}…

Materials Science · Physics 2015-05-19 S. K. Bose , J. Kudrnovský , V. Drchal , I. Turek

We study experimentally and theoretically the effects of disorder, nonlinear screening, and magnetism in semiconductor heterostructures containing a $\delta$-layer of Mn, where the charge carriers are confined within a quantum well and…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Vikram Tripathi , Kusum Dhochak , B. A. Aronzon , V. V. Rylkov , A. B. Davydov , Bertrand Raquet , Michel Goiran , K. I. Kugel