H. Krenn et al., SQUID MAGNETOCALORIMETRY OF DISORDERED AND ARTIFICIALLY STRUCTURED MAGNETIC SEMICONDUCTORS, Journal of magnetism and magnetic materials, 158, 1996, pp. 561-562
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.