We have measured the submillimeter wave ESR of II-VI and III-V semiconductors doped with Mn ions to study their electronic states. In Cd0.65Mn0.35Te, a crossover from the broadened ESR absorption to an ordinal easy-plane type antiferromagnetic resonance has been observed around 13 T. This crossover field gives the measure of the distribution of the exchange fields in the spinglass state. On the other hand, a ferromagnetic resonance has been observed in Ga1-xMnxAS(x = 0.029, 0.034). The g-value has been determined as g = 2.0 which corresponds to the Mn2+ ions. The saturation magnetization has also been estimated and considerable reduction was found.
- Diluted magnetic semiconductor