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

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This paper reports on the spin glass-like coexistence of competing magnetic orders in oxygen-deficient V2O5 nanoparticles having a broad size distribution. X-ray photoelectron spectroscopy yields the surface chemical stoichiometry of nearly…

We report on a monotonic reduction of Curie temperature in dilute ferromagnetic semiconductor (Ga,Mn)As upon a well controlled chemical-etching/oxidizing thinning from 15 nm down to complete removal of the ferro- magnetic response. The…

Materials Science · Physics 2012-06-29 O. Proselkov , D. Sztenkiel , W. Stefanowicz , M. Aleszkiewicz , J. Sadowski , T. Dietl , M. Sawicki

We have performed magnetic susceptibility and neutron scattering measurements on polycrystalline Ag-In-RE (RE: rare-earth) 1/1 approximants. In the magnetic susceptibility measurements, for most of the RE elements, inverse susceptibility…

Materials Science · Physics 2014-01-09 Soshi Ibuka , Kazuki Iida , Taku J Sato

We elaborate here why the antiferromagnetically ordered GdCrO$_3$ responds in a diamagnetic way under certain conditions, by monitoring the evolution of the microscopic global and local magnetic phases. Using high energy $\sim$ 0.3 eV…

Materials Science · Physics 2019-01-30 M. Tripathi , T. Chatterji , H. E. Fischer , R. Raghunathan , S. Majumder , R. J. Choudhary , D. M. Phase

We present an experimental and theoretical study of the magnetic field dependence of the mode frequency of thermally excited spin waves in rectangular shaped nanopillars of lateral sizes 60x100, 75x150, and 105x190 nm2, patterned from…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 A. Helmer , S. Cornelissen , T. Devolder , J. -V. Kim , W. van Roy , L. Lagae , C. Chappert

We present magnetization and specific heat data of a La5/3Sr1/3NiO4 single crystal in high magnetic fields. From the charge and spin stripe ordering temperatures, as well as a magnetic low temperature transition, we have constructed the…

Strongly Correlated Electrons · Physics 2014-03-13 R. Klingeler , B. Büchner , S-W. Cheong , M. Huecker

The results of magnetoconductivity measurements in GaInAs quantum wells are presented. The observed magnetoconductivity appears due to the quantum interference, which lead to the weak localization effect. It is established that the details…

Using a combination of magnetometry and magnetotransport techniques, we studied temperature and magnetic field behavior of magnetization in Py/Gd heterostructures. It was shown quantitatively that proximity with Py enhances magnetic order…

Mesoscale and Nanoscale Physics · Physics 2017-08-02 Pavel N. Lapa , Junjia Ding , John E. Pearson , Valentine Novosad , J. S. Jiang , Axel Hoffmann

We report magnetoresistance curves of CoFe nano-oxide specular spin valves of MnIr/CoFe/nano-oxidized CoFe/CoFe/Cu/CoFe/nano-oxidized CoFe/Ta at different temperatures from 300 to 20 K. We extend the Stoner-Wolfarth model of a common spin…

Materials Science · Physics 2009-11-11 J. Ventura , J. B. Sousa , M. A. Salgueiro da Silva , P. P. Freitas , A. Veloso

Magnetic and structural properties of magnetite nanoparticles stabilized in polyvinyl-alcohol thin films are investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR) and…

Weak localization and weak anti-localization are quantum interference effects in quantum transport in a disordered electron system. Weak anti-localization enhances the conductivity and weak localization suppresses the conductivity with…

Mesoscale and Nanoscale Physics · Physics 2014-09-05 Hai-Zhou Lu , Shun-Qing Shen

Most conventional magnetic materials used in the electronic devices are ferrites, which are composed of micrometer-size grains. But ferrites have small saturation magnetization, therefore the performance at GHz frequencies is rather poor.…

Materials Science · Physics 2015-03-19 J. V. I. Timonen , R. H. A. Ras , O. Ikkala , M. Oksanen , E. Seppala , K. Chalapat , J. Li , G. S. Paraoanu

We present calculations of the spin and phase relaxation rates in GaAs/AlGaAs $p$-type quantum wells. These rates are used to derive the temperature dependence of the weak-localization correction to the conductivity. In $p$-type quantum…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 L. E. Golub , S. Pedersen

One-dimensional quantum wires are considered as prospective elements for spin transport and manipulation in spintronics. We study spin dynamics in semiconductor GaAs-like nanowires with disorder and spin-orbit interaction by using a…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Carlos Echeverría-Arrondo , E. Ya. Sherman

We provide the first observation of weak localization in high carrier density two-dimensional electron gas in AlInN/GaN heterostructures; at low temperatures and low fields the conductivity increases with increasing magnetic field. Weak…

Mesoscale and Nanoscale Physics · Physics 2018-02-14 Leizhi Wang , Ming Yin , Asif Khan , Sakib Muhtadi , Fatima Asif , Eun Sang Choi , Timir Datta

We propose a method for nano-scale characterization of long range magnetic order in diluted magnetic systems to clarify the origins of the room temperature ferromagnetism. The GaN:Mn thin films are grown by metal-organic chemical vapor…

We demonstrate an exchange bias in (Ga,Mn)As induced by antiferromagnetic coupling to a thin overlayer of Fe. Bias fields of up to 240 Oe are observed. Using element-specific x-ray magnetic circular dichroism measurements, we distinguish a…

We induce surface carrier densities up to $\sim7\cdot 10^{14}$cm$^{-2}$ in few-layer graphene devices by electric double layer gating with a polymeric electrolyte. In 3-, 4- and 5-layer graphene below 20-30K we observe a logarithmic upturn…

Mesoscale and Nanoscale Physics · Physics 2018-02-21 R. S. Gonnelli , E. Piatti , A. Sola , M. Tortello , F. Dolcini , S. Galasso , J. R. Nair , C. Gerbaldi , E. Cappelluti , M. Bruna , A. C. Ferrari

The magnetic, transport, and structural properties of (Ga,Cr)As are reported. Zincblende Ga$_{1-x}$Cr$_{x}$As was grown by low-temperature molecular beam epitaxy (MBE). At low concentrations, x$\sim$0.1, the materials exhibit unusual…

Materials Science · Physics 2009-11-07 A. Dakhama , B. Lakshmi , D. Heiman

The nonlinear behavior of the Hall resistivity at low magnetic fields in single quantum well GaAs/In$_x$Ga$_{1-x}$As/GaAs heterostructures with degenerated electron gas is studied. It has been found that this anomaly is accompanied by the…

Disordered Systems and Neural Networks · Physics 2018-07-11 G. M. Minkov , A. V. Germanenko , O. E. Rut , A. A. Sherstobitov , B. N. Zvonkov