SQUID MAGNETOCALORIMETRY OF DISORDERED AND ARTIFICIALLY STRUCTURED MAGNETIC SEMICONDUCTORS

Thermal-wave SQUID susceptometry (TWS) is applied to determine the the rmally modulated magnetic moment of a magnetic semiconductor Pb1-x-ySn xMnyTe (x=0.72, y=0.03) and of a magnetic semiconductor superlattice [ EuTe(5)/PbTe(15)](400) together with their magnetic heat capacities wi thin one working cycle. The former system is a ferromagnet with reentr ance into a spin-glass behavior, the latter is an antiferromagnet-(EuT e)/paramagnet-(PbTe) superlattice grown by molecular beam epitaxy with few atomic layers (5/15) and 400 repeated periods. The surprisingly s trong ferromagnetism in the superlattice EuTe/PbTe is believed to aris e from the formation of coupled 2D polarons at the hetero-interfaces s tabilized by dipole-dipole interaction.