CARRIER-INDUCED MAGNETIC-PROPERTIES IN SMALL-GAP SEMICONDUCTORS

In the small-gap semiconductor Pb1-x-ySnyMnxTe the magnetic phase transition from a ferromagnetic to a spin-glass state at high carrier concentrations is studied. We present new data on magnetization, AC susceptibility and specific heat for various carrier concentrations showing the transition. We also present frequency-dependent AC susceptibility measurements. For the spin-glass sample there is a strong dependence on the measuring frequency, which follows the Vogel-Fulcher law. Furthermore, we calculate the phase boundary in the x-p magnetic phase diagram using the mean random field model. There is a satisfactory agreement between the experimental data and the calculations.