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Related papers: Proximity of LaOFeAs to a magnetic instability

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Electronic structure and magnetic properties of ZrFe$_2$ with a cubic Laves phase are investigated by calculations based on the density functional theory. The total magnetic moment (m) of 3.14 $\mu_B$ per formula unit (\emph{f.u.}) is…

Materials Science · Physics 2015-05-22 Wenxu Zhang , Wanli Zhang

Polarized and unpolarized neutron diffraction measurements have been carried out to investigate the iron magnetic order in undoped NdOFeAs. Antiferromagnetic order is observed below 141(6) K, which is in close proximity to the structural…

Superconductivity · Physics 2009-11-13 Ying Chen , J. W. Lynn , J. Li , G. Li , G. F. Chen , J. L. Luo , N. L. Wang , Pengcheng Dai , C. dela Cruz , H. A. Mook

We investigate magnetic ordering in metallic Ba[Fe(1-x)Mn(x)](2)As(2) and discuss the unusual magnetic phase, which was recently discovered for Mn concentrations x > 10%. We argue that it can be understood as a Griffiths-type phase that…

On experimental side, BaFe$_2$As$_2$ without doping has been made superconducting by applying appropriate pressure (2-6 GPa). Here, we use a full-potential linearized augmented plane wave method within the density-functional theory to…

Superconductivity · Physics 2009-04-08 Wenhui Xie , Mingli Bao , Zhenjie Zhao , Bang-Gui Liu

FeGe_2, and lightly doped compounds based on it, have a Fermi surface driven instability which drive them into an incommensurate spin density wave state. Studies of the temperature and magnetic field dependence of the resistivity have been…

Strongly Correlated Electrons · Physics 2009-10-28 T. E. Mason , C. P. Adams , S. A. M. Mentink , E. Fawcett , A. Z. Menshikov , C. D. Frost , J. B. Forsyth , T. G. Perring , T. M. Holden

Using state-of-the-art first-principles calculations we have elucidated the complex magnetic and structural dependence of LaOFeAs upon doping. Our key findings are that (i) doping results in an orthorhombic ground state and (ii) there is a…

Inelastic neutron scattering measurements demonstrate that the magnetic interactions in antiferromagnetic LaFeAsO are two-dimensional. Spin wave velocities within the Fe layer and the magnitude of the spin gap are similar to the…

Among magnetic thin films with perpendicular magnetic anisotropy (PMA), $L1_0$-ordered FePt has attracted significant attention because of its exceptionally strong PMA. However, the microscopic origin of its strong PMA has not been…

We use neutron diffraction and muon spin relaxation to study the effect of in-plane uniaxial pressure on the antiferromagnetic (AF) orthorhombic phase in BaFe$_2$As$_2$ and its Co- and Ni-substituted members near optimal superconductivity.…

We report extensive measurements of quantum oscillations in the normal state of the Fe-based superconductor LaFePO, (Tc ~ 6 K) using low temperature torque magnetometry and transport in high static magnetic fields (45 T). We find that the…

We performed magnetization and electrical resistivity measurements under high pressures of up to 19 GPa for FeTe0.92. The compound shows an anomaly in magnetization and resistivity at atmospheric pressure due to a structural distortion…

Combining density-functional theory calculations and microscopic tight-binding models, we investigate theoretically the electronic and magnetic properties of individual substitutional transition-metal impurities (Mn and Fe) positioned in…

Materials Science · Physics 2014-04-18 M. R. Mahani , M. Fhokrul Islam , A. Pertsova , C. M. Canali

With density functional theory, studied are the local magnetic moments in Fe-Al alloys depending on concentration and Fe nearest environment. At zero temperature, the system can be in different states: ferromagnetic, antiferromagnetic and…

Materials Science · Physics 2009-11-13 A. K. Arzhnikov , L. V. Dobysheva , M. A. Timirgazin

We present a unified, global perspective on the magnetic properties of strongly disordered electronic systems, with special emphasis on the case where the ground state is metallic. We review the arguments for the instability of the…

Strongly Correlated Electrons · Physics 2009-10-30 Subir Sachdev

The magnetic structures adopted by the Fe and Sm sublattices in SmFeAsO have been investigated using element specific x-ray resonant and non-resonant magnetic scattering techniques. Between 110 and 5 K, the Sm and Fe moments are aligned…

FeSe, despite being the structurally simplest compound in the family of iron-based superconductors, shows an astoundingly rich interplay of physical phenomena including nematicity and pressure-induced magnetism. Here, we present a…

The nature of the magnetic correlations in Fe-based superconductors remains a matter of controversy. To address this issue, we use inelastic neutron scattering to characterize the strength and temperature dependence of low-energy spin…

Superconductivity · Physics 2012-03-20 Zhijun Xu , Jinsheng Wen , Guangyong Xu , Songxue Chi , Wei Ku , Genda Gu , J. M. Tranquada

Using the degenerate double exchange Hamiltonian with on-site Coulomb interactions we show that there is an instability towards the displacement of the manganese ion in La_{1-x}Ca_{x}MnO_{3}. The result is a dipole moment due to the charge…

Strongly Correlated Electrons · Physics 2007-05-23 E. R. Sanchez Guajardo

The effect of high pressure (0 - 8 GPa) on the magnetic structure of polycrystalline samples of La0.5Ca0.5-xSrxMnO3 (0.1 -< x -< 0.4) manganites at 5 K is investigated using neutron diffraction technique. Application of pressure is found to…

Materials Science · Physics 2015-05-18 Indu Dhiman , Thierry Strässle , L. Keller , B. Padmanabhan , A. Das

Nematicity and magnetism are two key features in Fe-based superconductors, and their interplay is one of the most important unsolved problems. In FeSe, the magnetic order is absent below the structural transition temperature $T_{str}=90$K,…

Strongly Correlated Electrons · Physics 2016-06-07 Youichi Yamakawa , Seiichiro Onari , Hiroshi Kontani