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Related papers: Effects of Capping on the (Ga,Mn)As Magnetic Depth…

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We report a clear correspondence between changes in the Curie temperature and carrier density upon annealing in epitaxially grown (Ga,Mn)As layers with thicknesses in the range between 5 nm and 20 nm. The changes are dependent on the layer…

Materials Science · Physics 2009-11-07 B. Sorensen , J. Sadowski , R. Mathieu , P. Svedlindh , P. E. Lindelof

We have studied the depth-dependent magnetic and structural properties of as-grown and optimally annealed Ga[1-x]Mn[x]As films using polarized neutron reflectometry. In addition to increasing total magnetization, the annealing process was…

The effect of annealing at 250 C on the carrier depth profile, Mn distribution, electrical conductivity, and Curie temperature of (Ga,Mn)As layers with thicknesses > 200 nm, grown by molecular-beam epitaxy at low temperatures, is studied by…

Materials Science · Physics 2009-11-11 W. Limmer , A. Koeder , S. Frank , V. Avrutin , W. Schoch , R. Sauer , K. Zuern , J. Eisenmenger , P. Ziemann , E. Peiner , A. Waag

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

We demonstrate the manipulation of the Curie temperature of buried layers of the ferromagnetic semiconductor (Ga,Mn)As using nanolithography to enhance the effect of annealing. Patterning the GaAs-capped ferromagnetic layers into nanowires…

Materials Science · Physics 2009-11-11 K. F. Eid , B. L. Sheu , O. Maksimov , M. B. Stone , P. Schiffer , N. Samarth

(Ga,Mn)As and related diluted magnetic semiconductors play a major role in spintronics research because of their potential to combine ferromagnetism and semiconducting properties in one physical system. Ferromagnetism requires ~1-10% of…

Materials Science · Physics 2009-11-13 K. Olejnik , M. H. S. Owen , V. Novak , J. Masek , A. C. Irvine , J. Wunderlich , T. Jungwirth

We have used complementary neutron and x-ray reflectivity techniques to examine the depth profiles of a series of as-grown and annealed Ga[1-x]Mn[x]As thin films. A magnetization gradient is observed for two as-grown films and originates…

The dependence of the magnetic anisotropy of As-capped (Ga,Mn)As epilayers on the annealing parameters - temperature and time - has been investigated. A uniaxial magnetic anisotropy is evidenced, whose orientation with respect to the…

Materials Science · Physics 2007-05-23 V. Stanciu , P. Svedlindh

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…

Kerr rotation and Superconducting QUantum Interference Device (SQUID) magnetometry measurements were performed on ultrathin (Ga$_{0.95}$Mn$_{0.05}$)As layers. The thinner layers (below 250 \AA) exhibit magnetic properties different than…

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

A new scenario of the mechanism of intriguing ferromagnetic properties in Mn-doped magnetic semiconductor (Ga,Mn)As is examined in detail. We find that magnetic features seen in zero-field cooled and field cooled magnetizations are not…

Materials Science · Physics 2009-11-11 K. Hamaya , T. Koike , T. Taniyama , T. Fujii , Y. Kitamoto , Y. Yamazaki

We study the effects of growth temperature, Ga:As ratio and post-growth annealing procedure on the Curie temperature, Tc, of (Ga,Mn)As layers grown by molecular beam epitaxy. We achieve the highest Tc values for growth temperatures very…

Materials Science · Physics 2009-11-13 M Wang , R P Campion , A W Rushforth , K W Edmonds , C T Foxon , B L Gallagher

The effect of vacuum annealing thin films of the compensated ferrimagnetic half-metal Mn2RuxGa at temperatures from 250 to 400 degree Celsius is investigated. The 39.3 nm films deposited on (100) MgO substrates exhibit perpendicular…

Materials Science · Physics 2019-04-04 K. E. Siewierska , G. Atcheson , K. Borisov , M. Venkatesan , K. Rode , J. M. D. Coey

We have studied the effects of capping ferromagnetic Ga(1-x)Mn(x)As epilayers with a thin layer of undoped GaAs, and we find that even a few monolayers of GaAs have a significant effect on the ferromagnetic properties. In particular, the…

Condensed Matter · Physics 2009-11-10 M. B. Stone , K. C. Ku , S. J. Potashnik , B. L. Sheu , N. Samarth , P. Schiffer

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…

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

Using angle resolved photoemission we have investigated annealing-induced changes in Ga(1-x)Mn(x)As with x = 0.05. We find that the position of the Fermi energy is a function of annealing time and temperature. It is also established that…

Materials Science · Physics 2009-11-10 M. Adell , L. Ilver , J. Kanski , J. Sadowski , R. Mathieu

We report the results of a detailed study of the structural, magnetic and magnetotransport properties of as-grown and annealed Ga0.91Mn0.09As thin films grown on (311)A and (311)B GaAs substrates. The high Curie temperature and hole density…

Materials Science · Physics 2009-11-11 K. Y. Wang , K. W. Edmonds , L. X. Zhao , M. Sawicki , R. P. Campion , B. L. Gallagher , C. T. Foxon

High- and low-field magneto-transport measurements, as well as SQUID measurements of magnetization, were carried out on Ga1-xMnxAs epilayers grown by low temperature molecular beam epitaxy, and subsequently annealed under various…

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