Abstract
The magnetization, susceptibility, and specific heat of the semimagnetic semiconductor ( have been measured in the temperature range 0.5 K<T<300 K and in magnetic fields up to 25 T for x<18%. A transition to a spin-glass state is observed at low temperatures. The results indicate that a relatively strong antiferromagnetic (AF) nearest-neighbor interaction is present together with an AF long-range interaction of the type / or /. The magnetic moment on the Mn sites turns out to be about 4.4 Bohr magnetons and no deviation from a random distribution of the magnetic ions is observed. Based on these observations we calculated the thermodynamic properties with the extended nearest-neighbor pair correlation approximation. It appears that this approximation gives a good description of , M, and χ simultaneously with /=-30 K and /=-20/ K (R in units of the nearest-neighbor distance). Possible application of the model to other semimagnetic semiconductors and the possible origin of the exchange mechanism in ( are discussed.
- Received 9 September 1985
DOI:https://doi.org/10.1103/PhysRevB.33.7637
©1986 American Physical Society