The results of a study of the structural and magnetic properties of single-crystal samples of the diluted magnetic semiconductor Hg1−xCrxSe with different concentrations of chromium ions (0<x⩽0.07) in the temperature interval 50–300 K are reported. It is found that the boundary of the existence region of the homogeneous solid solution lies at chromium concentrations x<0.05. In samples with x⩾0.05 the sharp growth of the magnetic susceptibility in the region of the phase transition temperature is due not only to a transition to a phase similar to a spin-glass phase, which is observed in all the samples studied, but also to a ferromagnetic contribution from ferromagnetic inclusions of HgCr2Se4 and CrSe in those samples.

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.

No abstract

Experimental results of investigations of monocrystalline samples of Hg1−x−yCrxMnySe solid solution indicate, first, a considerable influence of manganese atoms introduced in Hg1−xCrxSe on the absolute values of physical parameters such as magnetic susceptibility, phase-transition temperature, mobility of conduction electrons, and the period of time during which the samples go over to the equilibrium state, and second, the formation of materials with improved electrophysical and clearly pronounced magnetic characteristics as compared with Hg1−xCrxSe samples with the same concentration of chromium ions.

Results are presented from a comprehensive study of helicon interferometry, nonresonant cyclotron absorption, and the Shubnikov–de Haas effect at microwave frequencies in the compound HgTe and in Hg1−xCdxTe solid solutions. Analysis of the experimental results and the already existing theoretical concepts suggests that in the gapless semiconductor HgTe and its solid solutions the static dielectric permittivity εs depends on the concentration of conduction electrons and the band parameters. Anomalous behavior of εs(x) is observed in the concentration interval 0.155⩽x⩽0.2 and is attributed to a change in the structure of the edges of the conduction and valence bands in Hg1−xCdxTe.