NATURAL AGING CHANGES IN GALVANOMAGNETIC PROPERTIES OF UNDOPED CADMIUM ANTIMONIDE

The change in the temperature and magnetic-field dependences of the Ha ll coefficient R(T) and R(H), and the change in the electrical conduct ivity sigma(T) and resistivity rho(H) of undoped cadmium antimonide in the course of natural aging for three years in air at room temperatur e have been studied. The initial dependences indicated that the low-te mperature conductivity is mainly due to holes in the valence band. The dependences R(T), sigma(T), R(H), and rho(H) of the aged samples can be explained by a two-band (valence and impurity) conduction model. Th e appearance of an impurity band in the aged samples is attributed to an increase, during aging, in the concentration of shallow acceptor ce nters due to structure defects mainly near the surface of a sample.