Ferromagnetic interactions in doped semiconductors and their nanostructures (invited)

The current status and prospects of research on ferromagnetism in tetrahedrally coordinated magnetic semiconductors and their nanostructures are reviewed. Results of a quantitative comparison between experimental and theoretical results, notably for Mn-based III-V and II-VI thin films and heterostructures, are presented. This comparison demonstrates that the current theory of the hole-mediated exchange interactions correctly describes the values of Curie temperatures T-C, magnetic anisotropy, and magnetic circular dichroism. On this basis, chemical trends are examined and shown to lead to the prediction of semiconductor systems with T-C that may exceed room temperature. Hopes associated with materials containing magnetic ions other than Mn are discussed. (C) 2001 American Institute of Physics.