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Related papers: Achieving High Curie Temperature in (Ga,Mn)As

200 papers

We present the magnetotransport properties of very thin (5 to 15 nm) single (Ga,Mn)As layers grown by low temperature molecular beam epitaxy. A lower (Ga,Mn)As thickness limit of 5 nm for the ferromagnetic phase and the dependence of the…

Materials Science · Physics 2009-11-07 B. S. Sorensen , J. sadowski , S. E. Andresen , P. E. Lindelof

X-ray diffraction, transmission electron microscopy, and magnetization measurements are employed to study the structural and magnetic properties of Mn-rich (Mn,Ga)As nanocrystals embedded in GaAs. These nanocomposites are obtained by…

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 examine the Mn concentration dependence of the electronic and magnetic properties of optimally annealed Ga1-xMnxAs epilayers for 1.35% < x < 8.3%. The Curie temperature (Tc), conductivity, and exchange energy increase with Mn…

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

We have grown the ferromagnetic semiconductor GaMnAs containing up to 10% Mn by migration enhanced epitaxy at a substrate temperature of 150^oC. The alternate supply of As2 molecules and Ga and Mn atoms made it possible to grow single…

We study the Curie temperature and hole density of (Ga,Mn)As while systematically varying the As-antisite density. Hole compensation by As-antisites limits the Curie temperature and can completely quench long-range ferromagnetic order in…

Materials Science · Physics 2007-05-23 R. C. Myers , B. L. Sheu , A. W. Jackson , A. C. Gossard , P. Schiffer , N. Samarth , D. D. Awschalom

The effect of outdiffusion of Mn interstitials from (Ga,Mn)As epitaxial layers, caused by post-growth low-temperature annealing, on their electronic- and band-structure properties has been investigated by modulation photoreflectance (PR)…

Materials Science · Physics 2015-06-16 O. Yastrubchak , T. Andrearczyk , J. Z. Domagala , J. Sadowski , L. Gluba , J. Zuk , T Wosinski

Heterostructures of two-dimensional (2D) van der Waals (vdW) magnets and topological insulators (TI) are of substantial interest as candidate materials for efficient spin-torque switching, quantum anomalous Hall effect, and chiral spin…

Materials with perpendicular magnetic anisotropy (PMA) effect with high Curie temperature ($T_C$) is essential in applications. In this work, $Cr_2Te_3$ thin films showing PMA with $T_C$ ranging from 165 K to 295 K were successfully grown…

Materials Science · Physics 2019-12-24 Hongxi Li , Linjing Wang , Tao Yu , Liang Zhou , Yang Qiu , Hongtao He , Fei Ye , Iam Keong Sou , Gan Wang

Real-time analysis of the growth modes during homoepitaxial (0001)GaN growth by plasma-assisted molecular beam epitaxy was performed using reflection high energy electron diffraction. A growth mode map was established as a function of Ga/N…

Applied Physics · Physics 2024-02-01 G. Koblmüller , S. Fernández-Garrido , E. Calleja , J. S. Speck

In molecular beam epitaxy, the spontaneous formation of GaN nanowires on Si(111) substrates at elevated temperatures is limited by the long incubation time that precedes nanowire nucleation. In this work, we present three unconventional…

We report epitaxial growth and characterization of GaN thin films on sapphire (0001) substrates using low temperature GaN intermediate layer by plasma assisted molecular beam epitaxy (PA-MBE) technique. As grown and annealed GaN thin films…

Materials Science · Physics 2015-09-09 Mahitosh Biswas

In this paper we show that the widely accepted method of the determination of Curie temperature (TC) in (Ga,Mn)As samples, based on the position of the peak in the temperature derivative of the resistivity,completely fails in the case of…

We report on detailed investigations of the electronic and magnetic properties of ferromagnetic GaMnAs layers, which have been fabricated by low-temperature molecular-beam epitaxy. Superconducting quantum interference device measurements…

Tuning magnetic properties of magnetic topological materials is of interest to realize elusive physical phenomena such as quantum anomalous hall effect (QAHE) at higher temperatures and design topological spintronic devices. However,…

Heavily-alloyed, 100 nm Ga1-xMnxAs (x>0.1) films are obtained via low temperature molecular beam epitaxy utilizing a combinatorial technique which allows systematic control of excess arsenic during growth. Reproducible, optimized…

Materials Science · Physics 2009-11-13 S. Mack , R. C. Myers , J. T. Heron , A. C. Gossard , D. D. Awschalom

The annealing-induced formation of (Mn,Ga)As nanocrystals in (Ga,Mn)As/GaAs superlattices was studied by X-ray diffraction, transmission electron microscopy and magnetometry. The superlattice structures with 50 A thick (Ga,Mn)As layers…

Materials Science · Physics 2015-06-03 J. Sadowski , J. Z. Domagala , R. Mathieu , A. Kovacs , P. Dluzewski

Growth of GaMnAs by molecular beam epitaxy is typically performed at low substrate temperatures (250C) and high As overpressures leading to the incorporation of excess As and Mn interstitials, which quench optical signals such as…

Materials Science · Physics 2009-09-29 M. Poggio , R. C. Myers , N. P. Stern , A. C. Gossard , D. D. Awschalom

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

We report the effect of annealing on the superconductivity of MgB2 thin films as functions of the postannealing temperature in the range from 700 C to 950 C and of the postannealing time in the range from 30 min to 120 min. On annealing at…

Superconductivity · Physics 2009-11-07 W. N. Kang , Eun-Mi Choi , Hyeong-Jin Kim , Hyun-Jung Kim , Sung-Ik Lee