MAGNETIZATION AND EXCITON SPECTROSCOPY OF THE DILUTED MAGNETIC SEMICONDUCTOR CD1-XCRXS

Free-exciton magnetoreflectance and magnetization are used to study th e p-d exchange interaction of Cd1-xCrxS (x = 0.0024, 0.0031, and 0.003 3). Magnetization data are well described by a simple crystal-field mo del taking into account static, tetragonal Jahn-Teller distortion suff ered by Cr2+ ions, as well as the hexagonal crystal field of CdS. In e ffect, a strong magnetic anisotropy of a single Cr2+ ion was found. Fr om the heavy-hole exciton splitting, and the Cr2+ ion spin deduced fro m magnetization data, the p-d exchange parameter was evaluated as N(0) beta = + 0.48 +/- 0.05 eV, using the previously obtained s-d exchange parameter: N(0)alpha = + 0.22 +/- 0.01 eV. These exchange parameters p rovide a reasonable description of the exciton splittings for a magnet ic field oriented along or perpendicularly to the crystal hexagonal ax is.