N. A. Chernova

Electric and magnetic characterization of impurity-induced states in diluted magnetic Pb1-yYbyTe semiconductors

In the present paper we report on results obtained by complex investigations of galvanomagnetic and magnetic properties of a diluted magnetic semiconductor Pb 1-y Yb y Te. Ytterbium doping modifies the energy spectrum of charge carriers in lead telluride by formation of deep impurity levels, moving from valence to forbidden band with increase of ytterbium content. The paramagnetic Curie-Weiss response observed has revealed a small fraction of Yb ions in magnetically active Yb 3 charge state, while the majority of impurity ions are in non-magnetic Yb 2+ state. We couple the magnetic and galvanomagnetic data in a model of charge carriers energy spectrum in Pb 1-y Yb y Te, for which energy position and electron population of the ytterbium level are derived as a function of impurity concentration.

Parameters of defect states in alloys irradiated with electrons

This paper is devoted to the investigation of galvanomagnetic effects in electron-irradiated (, , ) n- and p- alloys in the vicinity of the insulator-metal transition induced by pressure . In the frame of the two-band model, the dependence of the Hall constant on the magnetic field was calculated and found to be in a good agreement with experimental data. The main parameters of charge carriers in irradiated alloys were determined. It was shown that in the metal phase the hole concentration increases under pressure due to the motion of the energy bands at the Brillouin zone L-point and the flow of electrons from the valence band to the radiation defect band . By comparing theoretical and experimental dependences of hole concentration on pressure the parameters of the irradiation-induced defect band were determined.