ANISOTROPIC MAGNETIC-SUSCEPTIBILITY OF HEXAGONAL CO-BASED DILUTED MAGNETIC SEMICONDUCTORS

We present magnetic-susceptibility data for two new cobalt-based diluted magnetic semiconductor systems with the wurtzite lattice structure: Cd1-xCoxSe and Cd1-xCoxS. At low temperatures, the magnetic susceptibility of both systems is anisotropic. We analyze the low-temperature data within the framework of the crystal-field model, including pair interaction. The analysis yields the value of the zero-field splitting D/kB of the Co2+-ion orbital ground state as 1.00.1 K for the selenides, and as 0.850.1 K for the sulfides. From quantitative analysis of the high-temperature data, we obtain the value of the nearest-neighbor Co2+-Co2+ exchange integral J/kB for Cd1-xCoxSe to be -375 K. © 1990 The American Physical Society.