Microstructure, magnetic, and spin-dependent transport properties of (Zn,Cr)Te films fabricated by magnetron sputtering

Abstract

Chromium doped zinc telluride thin films with various doping concentrations are fabricated by magnetron sputtering. These films are ferromagnetic and the Curie temperature increases with Cr concentration. X-ray diffraction, transmission electron microscopy, and magnetic circular dichroism characterizations show that the films are free of Cr 1−x Te x impurities and the ferromagnetism is intrinsic. The transport study shows that the resistivity and magnetoresistance are governed by variable range hopping at low temperatures. A negative magnetoresistance as large as −57% is observed at 5 K. The magnetoresistance and its temperature dependence can be well explained by a model involving an increase in the localization length of carriers with a magnetic field in the hopping region. An anomalous Hall effect is also observed and a possible origin of the sign difference between the anomalous Hall resistance and ordinary Hall resistance is discussed.

Transition from antiferromagnetic to ferromagnetic β-Co(OH)2 with higher Curie temperature

“…Due to this Coulomb gap between two interacting electrons, the density of states become nearly equal to zero near the Fermi level [40,41]. As a result, the logarithmic resistivity follows the linear dependency on T −1/2 (ES-VRH) instead of T −1/3 (Mott-VRH) [42,43]. Figures 6(c (ES-VRH).…”

Magnetic hard gap due to bound magnetic polarons in the localized regime

“…At the same time, the transport switches to ES type from Mott hopping. A number of DMS systems have been reported to exhibit ES type hopping as a result of spin-spin interaction and BMP formation 8 33 .…”

Ferromagnetic Resonance in CdTe:Cr Single Crystals Containing Dopant-Related Macrodefects

“…As in the case of other DMS doped with transition metals [11], there exist two different approaches concerning this problem. According to the first one, the appearance of room-temperature ferromagnetism was explained by ferromagnetic interaction of double ionized Cr atoms, randomly substituting metal ones in II-VI lattice [5][6][7]. Contrary, the other suggests that ferromag- * corresponding author; e-mail: kuzma@univ.rzeszow.pl netic ordering originates from Cr-related second phases buried in the host matrix [12][13][14].…”