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Related papers: Weak localization in ferromagnetic (Ga,Mn)As nanos…

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We determine the spin susceptibility $\chi$ in the weak interaction regime of a tunable, high quality, two-dimensional electron system in a GaAs/AlGaAs heterostructure. The band structure effects, modifying mass and g-factor, are carefully…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Y. -W. Tan , J. Zhu , H. L. Stormer , L. N. Pfeiffer , K. W. Baldwin , K. W. West

Weak localization in graphene is studied as a function of carrier density in the range from 1 x $10^{11}$\,cm$^{-2}$ to 1.43 x $10^{13}$\,cm$^{-2}$ using devices produced by epitaxial growth onto SiC and CVD growth on thin metal film. The…

We report a large tunneling anisotropic magnetoresistance (TAMR) in a thin (Ga,Mn)As epilayer with lateral nanoconstrictions. The observation establishes the generic nature of this effect, which originates from the spin-orbit coupling in a…

We study magnetic, transport and thermal properties of Cobalt carbide nanocomposite with a mixture of Co2C and Co3C phases in 1:1 ratio, with an average particle diameter of 40$\pm 15$ nm. We show that the behavior of the nanocomposite is…

Strongly Correlated Electrons · Physics 2020-03-31 Nirmal Roy , Arpita Sen , Prasenjit Sen , S. S. Banerjee

We have studied the local electronic structure of LaMn0.5Co0.5O3 using soft-x-ray absorption spectroscopy at the Co-L_3,2 and Mn-L_3,2 edges. We found a high-spin Co^{2+}--Mn^{4+} valence state for samples with the optimal Curie…

Strongly Correlated Electrons · Physics 2008-03-18 T. Burnus , Z. Hu , H. H. Hsieh , V. L. J. Joly , P. A. Joy , M. W. Haverkort , Hua Wu , A. Tanaka , H. -J. Lin , C. T. Chen , L. H. Tjeng

Temperature dependent weak localization is measured in metallic nanowires in a previously unexplored size regime down to width $w=5$ nm. The dephasing time, $\tau_{\phi}$, shows a low temperature $T$ dependence close to quasi-1D theoretical…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 D. Natelson , R. L. Willett , K. W. West , L. N. Pfeiffer

We have studied the magnetic field effect on low frequency dielectric properties of Pr0.6Ca0.4MnO3/polyvinylidene fluoride nanocomposite with 22.5% volume fraction of Pr0.6Ca0.4MnO3 nanoparticles. A strong magnetodielectric response was…

Materials Science · Physics 2011-12-16 K. Devi Chandrasekhar , A. K. Das , A. Venimadhav

We have performed a muon spin rotation study on polycrystalline samples of electron-doped layered manganites, La$_{2-2x}$Sr$_{1+2x}$Mn$_2$O$_7$ (0.4< x<1), in order to investigate the local magnetic structure and spin dynamics. Our results…

Strongly Correlated Electrons · Physics 2007-05-23 A. I. Coldea , S. J. Blundell , C. A. Steer , J. F. Mitchell , F. L. Pratt

We investigated the magnetotransport in high quality ferromagnetic (Ga,Mn)As films and wires. At low temperature the conductivity decreases with decreasing temperature without saturation down to 20 mK. Here we show, that the conductivity…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Daniel Neumaier , Markus Schlapps , Ursula Wurstbauer , Janusz Sadowski , Matthias Reinwald , Werner Wegscheider , Dieter Weiss

The rare earth neodymium arguably exhibits the most complex magnetic ordering and series of magnetic phase transitions of the elements. Here we report the results of small-angle neutron scattering (SANS) measurements as a function of…

We present a theoretical study of (Ga,Mn)(As,C) diluted magnetic semiconductors with high C acceptor density that combines insights from phenomenological model and microscopic approaches. A tight-binding coherent potential approximation is…

Materials Science · Physics 2007-05-23 T. Jungwirth , J. Masek , Jairo Sinova , A. H. MacDonald

We report on the determination of micromagnetic parameters of epilayers of the ferromagnetic semiconductor (Ga,Mn)As, which has easy axis in the sample plane, and (Ga,Mn)(As,P) which has easy axis perpendicular to the sample plane. We use…

Temperature dependent X-ray diffraction and Raman spectroscopic studies were carried out on the flux grown single crystals of gallium ferrite with Ga:Fe ratio of 0.9:1.1. Site occupancy calculations from the Rietveld refinement of the X-ray…

Materials Science · Physics 2011-10-24 Somdutta Mukherjee , Rajeev Gupta , Ashish Garg

We study the nanoscale phase coexistence of ferromagnetic metallic (FMM) and antiferromagnetic insulating (AFI) regions by including the effect of AF superexchange and weak disorder in the double exchange model. We use a new Monte Carlo…

Strongly Correlated Electrons · Physics 2009-11-10 Sanjeev Kumar , Pinaki Majumdar

We have studied the field dependence of the magnetization in epilayers of the diluted magnetic semiconductor Ga(1-x)Mn(x)As for 0.0135 < x < 0.083. Measurements of the low temperature magnetization in fields up to 3 T show a significant…

Condensed Matter · Physics 2009-11-07 S. J. Potashnik , K. C. Ku , S. H. Chun , R. F. Wang , M. B. Stone , N. Samarth , P. Schiffer

55Mn and 139La NMR measurements on a high quality single crystal of ferromagnetic (FM) La0.80Ca20MnO3 demonstrate the formation of localized Mn(3+,4+) states below 70 K, accompanied with strong anomalous increase of certain FM neutron Bragg…

Strongly Correlated Electrons · Physics 2009-11-07 G. Papavassiliou , M. Belesi , M. Fardis , M. Pissas , J. Dolinsek , C. Dimitropoulos , J. P. Ansermet

The magnetic anisotropy (MA) of Mo/Au/Co0.9Fe0.1/Au/MgO(0.7 - 3 nm)/Au/Co0.9Fe0.1/Au heterostructure has been investigated at room temperature as a function of MgO layer thickness (tMgO). Our studies show that while the MA of the top layer…

Materials Science · Physics 2017-08-25 Kinga Lasek , Leszek Gladczuk , Maciej Sawicki , Pavlo Aleshkevych , Piotr Przyslupski

We report the observation of nuclear magnetic resonance (NMR) in a ferromagnet-semiconductor heterostructure in the presence of a spin-polarized current. Spin-polarized electrons injected from a metallic ferromagnet generate a large nuclear…

Condensed Matter · Physics 2009-11-10 J. Strand , B. D. Schultz , A. F. Isakovic , X. Lou , C. J. Palmstrom , P. A. Crowell

The magnetic and transport properties are systematically studied on the single crystal $Na_{0.55}CoO_2$ with charge ordering and divergency in resistivity below 50 K. A long-range ferromagnetic ordering is observed in susceptibility below…

Strongly Correlated Electrons · Physics 2009-11-11 C. H. Wang , X. H. Chen , T. Wu , X. G. Luo , G. Y. Wang , J. L. Luo

Mixed valent manganites are noted for their unusual magnetic,electronic and structural phase transitions. The La1-xCaxMnO3 phase diagram shows that below transition temperatures in the range 100-260 K, compounds with 0.2 < x < 0.5 are…

Condensed Matter · Physics 2009-11-07 James C. Loudon , Neil D. Mathur , Paul A. Midgley