The influence of the semiconductor properties on the Mössbauer emission spectra of 57Co cobalt oxide

Abstract 57 CO 1− x O Mossbauer sources were prepared at 1000°C and different oxygen pressures. The number x of Co vacancies, which depend on the oxygen pressure during the preparation, determine the Fe 3+ fraction in the emission spectrum of the source at room-temperature. A theoretical model allows a correlation between these quantities. Measurements on 57 Co 1− x O sources between room-temperature and 1000°C proved that at temperatures above 500°C electron relaxations between the 57 Fe m impurity, introduced in the lattice as a consequence of the 57 Co decay, and the valence band take place. A theoretical model was developed which describes these relaxation phenomena reasonably well.