Optical, magnetic, and transport behaviors of Ge1−xMnxTe ferromagnetic semiconductors grown by molecular-beam epitaxy

Abstract

The optical, magnetic, and transport behaviors of Ge1−xMnxTe (x=0.24 and 0.55) grown by solid-source molecular-beam epitaxy are investigated. X-ray diffraction shows that Ge1−xMnxTe crystallizes in rocksalt structure. The temperature-dependent magnetization (M-T) for x=0.55 sample gives a Curie paramagnetic temperature of θp∼180 K, which is consistent with the temperature-dependent resistivity ρ(T) measurement. Anomalous Hall effect is clearly observed in the samples and can be attributed to extrinsic skew scattering based on the scaling relationship of ρxy∝ρxx1.06. The magnetoresistance of Ge1−xMnxTe is isotropic and displays a clear hysterestic loop at low temperature, which resembles that of giant-magnetoresistance granular system in solids.

Half-metallicity and magnetism of GeTe doped with transition metals V, Cr, and Mn: A theoretical study from the viewpoint of application in spintronics

“…[1][2][3][4][5][6][7][8] Ferromagnetic (FM) order was observed for the Cr, Mn, and Fe doped films, whereas Ti, V, Co, and Ni doped films were found to be paramagnetic. 2 The Curie temperatures T c of these thin films have been found to depend on the type and concentration of the dopants, with a high value of 140 K, reported for Ge 1Àx Mn x Te for x ¼ 0.51.…”

Heat-Treatment-Induced Switching of Magnetic States in the Doped Polar Semiconductor Ge1−xMnxTe

“…The onset temperature T c of magnetic order was reported to increase linearly with x with maximum values around 165 K for x  = 0.535. More recent works have focussed on thin films of Ge 1− x Mn x Te, finding a carrier-induced enhancement of the T c values up to 200 K for x  = 0.08 and hole concentrations of about 1.6 × 10 21  cm −3 46474849. The emergence of ferromagnetism in bulk and thin films of Ge 1− x Mn x Te has been considered in an RKKY framework plus possible antiferromagnetic correlations by Mn–Mn direct exchange354143.…”

Effect of hydrostatic pressure in degenerate Ge1−xMnxTe

“…It can be seen that the M͑T͒ curve goes to zero at T C ‫ء‬ ϳ 100 K, which possibly originates from FM Ge 0.9 Mn 0.1 Te clusters that give rise to magnetic short range ordering. 5 A shallow minimum M in ͑T͒ at T R =34Ϯ 10 K is observed at ambient pressure. We have previously established that the T R correlates directly with the T C for different Mn compositions.…”

“…We have previously established that the T R correlates directly with the T C for different Mn compositions. 5 The effect of an external pressure ͑P͒ on ͑T͒ has shifted T R toward higher temperature ͑indicated by the arrows in Fig. 1͒ and caused a decrease in .…”