Yu. S. Paranchich

Influence of Mn concentration on the physical phenomena in the semimagnetic semiconductor Hg1−x−yCrxMnySe

Results are presented from a study of the magnetic susceptibility and electron spin resonance (ESR) on Cr3+ and Mn2+ ions in a series of samples of the semimagnetic semiconductor Hg1−x−yCrxMnySe with x=0.02 and 0.01⩽y⩽0.08. The experimental results show that the structure of the ESR spectrum and the character of its shift with respect to magnetic field as the temperature changes depend on the ratio of the concentrations of chromium and manganese ions, which form two interacting substructures. The observed transition of Hg1−x−yCrxMnySe to a spin glass phase is not related to the distortion of the symmetry of the crystal lattice. The shared and distinctive properties of the systems Hg1−xCrxSe and Hg1−x−yCrxMnySe are determined.

Relaxation effects in Gd-doped HgSe

GdxHg1-xSe (0 <x < 0.01) single crystals were grown, and their transport properties and electron spin resonance spectra were studied between 77 and 400 K in magnetic fields of up to 1.6 T. The cooling rate was found to influence the properties of the crystals. Their low-temperature conductivity varies by almost one order of magnitude, depending on the cooling rate. The Hall mobility in Gd-doped HgSe far exceeds that in nominally undoped HgSe with the same carrier concentration. The cooling rate also has a strong effect on the temperature and field dependences of the Hall coefficient and the electron spin resonance spectrum. The results are interpreted in terms of Gd precipitation caused by the lattice strain developing during cooling.

Growth and Properties of V-Doped HgSe Crystals

HgSe〈V〉 crystals with a vanadium concentration ranging from 1024to 1026m–3were grown, and their transport properties were investigated between 77 and 400 K in magnetic fields of up to 12.73 kA/m. The effect of long-term annealing in Se vapor on the electron concentration and mobility in the crystals was studied. The n(NV), μ(T), and RH(T) data obtained before and after annealing suggest that the V dopant produces a resonance donor level in the conduction band of HgSe at EV≃ 0.250–0.260 eV.

Growth and Properties of V-Doped CdxHg1 – xTe Crystals

CdxHg1 – xTe〈V〉 (x= 0.9–0.95) crystals were prepared by two versions of Bridgman growth, and their optical homogeneity and transport properties were studied. The electrical resistivity of the crystals was 104to 108 Ω m. From the temperature dependences of the Hall coefficient, the activation energy of the vanadium level in CdxHg1 – xTe〈V〉 was determined to be 0.73–0.82 eV.