Magnetic properties of diluted magnetic semiconductors: A review (invited)

Diluted magnetic semiconductors (DMS) are semiconducting alloys containing a random distribution of substitutional magnetic ions (e.g., Mn^{+ +} in Cd_1-xMn_xSe). Magnetic properties of DMS - such as spin glass behavior due to lattice frustration, magnon excitations in a random system of spins, superexchange, and short range antiferromagnetic order - are of considerable interest in their own right. In addition, understanding these properties is important because they strongly influence the electronic phenomena in DMS via the sp-d exchange interaction between the band electrons and the localized magnetic moments. We review the most recent results concerning magnetic susceptibility, Mn⁺⁺-Mn⁺⁺ nearest-neighbor exchange, and magnetic short-range order in these materials. On this basis, we can present a fairly complete and unified picture of magnetic properties of DMS. In addition, we point out some of the issues and challenges that lie ahead.