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Related papers: The Hall effect and hole densities in high Tc GaMn…

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The Curie temperature TC is investigated as a function of the hole concentration p in thin films of ferromagnetic semiconductor (Ga,Mn)As. The magnetic properties are probed by transport measurements and p is varied by the application of an…

Materials Science · Physics 2015-05-18 Y. Nishitani , D. Chiba , M. Endo , M. Sawicki , F. Matsukura , T. Dietl , H. Ohno

The temperature dependence of the Hall coefficient of a series of ferromagnetic Ga(1-x)Mn(x)As samples is measured in the temperature range 80K < T < 500K. We model the Hall coefficient assuming a magnetic susceptibility given by the…

We show that by annealing Ga1-xMnxAs thin films at temperatures significantly lower than in previous studies, and monitoring the resistivity during growth, an unprecedented high Curie temperature Tc and conductivity can be obtained. Tc is…

Materials Science · Physics 2009-11-07 K. W. Edmonds , K. Y. Wang , R. P. Campion , A. C. Neumann , N. R. S. Farley , B. L. Gallagher , C. T. Foxon

Transport properties of GaAs/{\delta}<Mn>/GaAs/In\timesGa1-\timesAs/GaAs structures containing InxGa1-xAs (\times {\approx} 0.2) quantum well (QW) and Mn delta layer (DL) with relatively high, about one Mn monolayer (ML) content, are…

The Hall effect is investigated for eight superconducting Fe(Se_0.5_Te_0.5_) thin films grown on MgO and LaSrAlO_4_ substrates with different transition temperatures (T_c_). The normal Hall coefficients (R_H_) have positive values with…

Superconductivity · Physics 2015-05-14 I. Tsukada , M. Hanawa , S. Komiya , T. Akiike , R. Tanaka , Y. Imai , A. Maeda

The effect of microscopic Mn cluster distribution on the Curie temperature (Tc) is studied using density-functional calculations. We find that the calculated Tc depends crucially on the microscopic cluster distribution, which can explain…

Materials Science · Physics 2007-05-23 Teemu Hynninen , Hannes Raebiger , Andres Ayuela , J. von Boehm

We provide experimental evidence that the upper limit of ~110 K commonly observed for the Curie temperature T_C of Ga(1-x)Mn(x)As is caused by the Fermi-level-induced hole saturation. Ion channeling, electrical and magnetization…

Materials Science · Physics 2009-11-10 K. M. Yu , W. Walukiewicz , T. Wojtowicz , W. L. Lim , X. Liu , U. Bindley , M. Dobrowolska , J. K. Furdyna

Magnetite epitaxial thin films have been prepared by pulsed laser deposition at 340 C on MgO and Si substrates. One key result is that the thin film properties are almost identical to the properties of bulk material. For 40 - 50 nm thick…

Materials Science · Physics 2007-05-23 D. Reisinger , P. Majewski , M. Opel , L. Alff , R. Gross

Temperature-dependence and magnetic field-dependence of the Hall effect and the magnetic property in manganese-oxide thin films are studied. The spontaneous magnetization and the Hall resistivity are obtained for a various of magnetic…

Condensed Matter · Physics 2009-10-28 Liang-Jian Zou

We investigate the relationship between the Curie temperature TC and the carrier density p in the ferromagnetic semiconductor (Ga,Mn)As. Carrier densities are extracted from analysis of the Hall resistance at low temperatures and high…

Mesoscale and Nanoscale Physics · Physics 2013-03-12 M. Wang , K. W. Edmonds , B. L. Gallagher , A. W. Rushforth , O. Makarovsky , A. Patanè , R. P. Campion , C. T. Foxon , V. Novak , T. Jungwirth

The anomalous Hall effect in metal-insulator-semiconductor structures having thin (Ga,Mn)As layers as a channel has been studied in a wide range of Mn and hole densities changed by the gate electric field. Strong and unanticipated…

Materials Science · Physics 2015-03-17 D. Chiba , A. Werpachowska , M. Endo , Y. Nishitani , F. Matsukura , T. Dietl , H. Ohno

We have measured the longitudinal resistivity and the Hall resistivity in the ab-plane of highly c-axis-oriented MgB2 thin films. In the normal state, the Hall coefficient (R_H) behaves as R_H ~ T with increasing temperature (T) up to 130 K…

Superconductivity · Physics 2009-11-07 W. N. Kang , Hyeong-Jin Kim , Eun-Mi Choi , Heon Jung Kim , Kijoon H. P. Kim , H. S. Lee , Sung-Ik Lee

The effect of short-time and long-time annealing at 250C on the conductivity, hole density, and Curie temperature of GaMnAs single layers and GaMnAs/InGaMnAs heterostructures is studied by in-situ conductivity measurements as well as Raman…

Condensed Matter · Physics 2009-11-10 W. Limmer , A. Koeder , S. Frank , M. Glunk , W. Schoch , V. Avrutin , K. Zuern , R. Sauer , A. Waag

The magnetization and hole distribution of Mn clusters in (Ga,Mn)As are investigated by all-electron total energy calculations using the projector augmented wave method within the density-functional formalism. It is found that the…

Materials Science · Physics 2009-11-11 H. Raebiger , A. Ayuela , J. von Boehm

Spin chirality in metallic materials with non-coplanar magnetic order can give rise to a Berry phase induced topological Hall effect. Here, we report the observation of a large topological Hall effect in high-quality films of Mn$_{1.5}$PtSn…

The resistivity, temperature, and magnetic field dependence of the anomalous Hall effect in a series of metallic Ga1-xMnxAs thin films with 0.015=<x=<0.08 is presented. A quadratic dependence of the anomalous Hall resistance on the…

Materials Science · Physics 2009-11-07 K W Edmonds , R P Campion , K-Y Wang , A C Neumann , B L Gallagher , C T Foxon , P C Main

We have investigated the effect of doping by Te on the anomalous Hall effect in Ga1-xMnxAs (x = 0.085). For this relatively high value of x the temperature dependence of resistivity shows an insulating behavior. It is well known that in…

Materials Science · Physics 2009-11-10 Sh. U. Yuldashev , H. C. Jeon , H. S. Im , T. W. Kang , S. H. Lee , J. K. Furdyna

Various experimental results providing information on thermodynamic density of states in (Ga,Mn)As are analyzed theoretically assuming that holes occupy GaAs-like valence bands. Allowing for Gaussian fluctuations of magnetization, the…

Materials Science · Physics 2011-07-29 C. Sliwa , T. Dietl

We report Curie temperatures up to 150 K in annealed Ga1-xMnxAs epilayers grown with a relatively low As:Ga beam equivalent pressure ratio. A variety of measurements (magnetization, Hall effect, magnetic circular dichroism and Raman…

Doping nonmagnetic semiconductors with magnetic impurities is a feasible way to obtain diluted magnetic semiconductors (DMSs). It is generally accepted that for the most extensively studied DMS, (Ga, Mn)As, its highest Curie temperature…

Materials Science · Physics 2025-05-08 Xiang Li , Jia-Wen Li , Jing-Yang You , Gang Su , Bo Gu
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