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Related papers: Mn and Fe Impurities in MgB_{2}

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A formalism is developed to treat magnetic impurities in a Mott-Hubbard antiferromagnetic insulator within a representation involving multiple orbitals per site. Impurity scattering of magnons is found to be strong when the number of…

Strongly Correlated Electrons · Physics 2009-10-31 Avinash Singh , Prasenjit Sen

In order to find out if magnetic impurities can mediate interactions between quasiparticles in metals, we have measured the effect of a magnetic field B on the energy distribution function f(E) of quasiparticles in two silver wires driven…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. Anthore , F. Pierre , H. Pothier , D. Esteve

Effects of magnetic impurity on the superconductivity has been investigated in Mg1-xMnB2. With increase of Mn concentration x, the lattice constant c (perpendicular to the boron sheet) decreases at a rate of -1.4 % (= dlnc/dx), while a…

Superconductivity · Physics 2009-11-07 Sheng Xu , Yutaka Moritomo , Kenichi Kato , Arao Nakamura

Metals with many bands at the Fermi level can have different band dependent gaps in the superconducting state. The absence of translational symmetry at an interface can induce interband scattering and modify the superconducting properties.…

Condensed Matter · Physics 2009-11-07 E. Bascones , F. Guinea

We study effects of nonmagnetic impurities in a Spin Bose-Metal (SBM) phase discovered in a two-leg triangular strip spin-1/2 model with ring exchanges (D. N. Shenget al, arXiv:0902.4210). This phase is a quasi-1D descendant of a 2D spin…

Strongly Correlated Electrons · Physics 2010-09-21 Hsin-Hua Lai , Olexei I. Motrunich

We present a computational study of individual and pairs of substitutional Mn impurities on the (110) surface of GaAs samples based on density functional theory. We focus on the anisotropy properties of these magnetic centers and their…

Strongly Correlated Electrons · Physics 2011-08-29 M. Fhokrul Islam C. M. Canali

We present the first results of directional point-contact measurements in Mg_{1-x}Mn_{x}B_2 single crystals, with x up to 0.015 and bulk T_c down to 13.3 K. The order parameters Delta_{sigma} and Delta_{pi} were obtained by fitting the…

In this paper we summarize the effects of magnetic and nonmagnetic impurities on the spin dynamics in Febased superconductors and their parent compounds. The effects of chemical substitution, vacancies, and disorder on the suppression or…

We study nonmagnetic impurity effects in MgB$_{2}$ using the quasiclassical equations of superconductivity for a weak-coupling two-band model. Parameters in the model are fixed so as to reproduce experiments on MgB$_{2}$ as closely as…

Superconductivity · Physics 2009-11-10 Koichi Watanabe , Takafumi Kita

Using first-principles calculations, we investigated the impact of chromium (Cr) and vanadium (V) impurities on the magnetic anisotropy and spin polarization in Fe/MgO magnetic tunnel junctions. It is demonstrated using layer resolved…

Materials Science · Physics 2016-01-25 A. Hallal , B. Dieny , M. Chshiev

Applying the generalization of the model for chain formation in break-junctions [JPCM 24, 135501 (2012)], we study the effect of light impurities on the energetics and elongation properties of Pt and Ir chains. Our model enables us with a…

Mesoscale and Nanoscale Physics · Physics 2014-10-02 Solange Di Napoli , Alexander Thiess , Stefan Blügel , Yuriy Mokrousov

We investigate a magnetic impurity in Bernal stacked bilayer graphene by a non-perturbative numerical exact approach. In the two cases we study, impurity is placed on the top of two different sublattices (A and B) in bilayer graphene. We…

Strongly Correlated Electrons · Physics 2012-06-05 J. H. Sun , F. M. Hu , H. K. Tang , H. Q. Lin

The effect of a magnetic (S=1/2) impurity coupled to a 2D system of correlated electrons (described by the t--J model) is studied by exact diagonalisations. It is found that, if the exchange coupling of the impurity with the neighboring…

Condensed Matter · Physics 2016-08-31 D. Poilblanc , D. J. Scalapino , W. Hanke

The effects of dilute Zn impurities on the uniform magnetic susceptibility are calculated in the normal metallic state for a model of the spin fluctuations of the layered cuprates. It is shown that scatterings from extended impurity…

Strongly Correlated Electrons · Physics 2009-10-31 N. Bulut

A new route to $d^0$ magnetism is established with help of the first principles methods. Non-magnetic interstitial impurities from group 14 in the periodic table are found to induce $p$-orbital magnetism in polycrystalline PbO-type…

Materials Science · Physics 2015-06-15 J. Berashevich , A. Reznik

Measurements have been performed of the resistivity of the samples of MgB2, AlB2 and AgB2. The samples show presence of impurities. Analyzing the data in terms of the impurity scattering, electron-phonon scattering, and weak localization it…

Superconductivity · Physics 2009-11-11 R. Lal , V. P. S. Awana , K. P. Singh , H. Kishan , A. V. Narlikar

The substitution of Mn in the III-V diluted magnetic semiconductors leads to a strong electron scattering on impurities. Besides the features induced in the valence band by the hybridization with the Mn d-states, also the conduction band is…

Materials Science · Physics 2007-05-23 J. Masek , F. Maca

We have performed ab initio calculations to systematically investigate electronic properties and magnetism of insulating non-magnetic beryllium monoxide nanotubes induced by non-magnetic sp impurities: boron, carbon and nitrogen. We found…

Materials Science · Physics 2008-05-14 M. A. Gorbunova , I. R. Shein , Yu. N. Makurin , V. V. Ivanovskaya , V. S. Kijko , A. L. Ivanovskii

Magnetoresistance measurements on the magnetic semiconductor (In,Mn)Sb suggest that magnetic scattering in this material is dominated by isolated Mn$^{2+}$ ions located outside the ferromagnetically-ordered regions when the system is below…

Other Condensed Matter · Physics 2009-11-11 M. Csontos , T. Wojtowicz , X. Liu , M. Dobrowolska B. Jankó , J. K. Furdyna , G. Mihály

We theoretically consider the effects of having unintentional charged impurities in laterally coupled two-dimensional double (GaAs) quantum dot systems, where each dot contains one or two electrons and a single charged impurity in the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Nga T. T. Nguyen , S. Das Sarma