Diluted magnetic semiconductor superlattices for magnetic studies of dimensional crossover (invited)

Diluted magnetic semiconductor Cd1−xMnxTe-CdTe superlattices with x=0.069, 0.13, 0.15, and 0.20 and various layer thicknesses were grown by molecular-beam epitaxy for optical and magnetic studies of dimensional crossover. X-ray diffraction patterns, low-temperature photoluminescence spectra, and ac magnetic susceptibility measurements were used to verify the integrity of these structures. In particular, the magnetic studies showed the spin-glass transition present in the thicker magnetic layers to broaden and eventually disappear with decreasing thickness, suggesting the inability of the two-dimensional system to support long-range spin-glass order.