Ferromagnetism in dilute magnetic semiconductors and new materials for spintronics

Spintronics materials may be classified under concentrated magnetic semiconductors, semimetals and half-metals, semimagnetic semiconductors, and dilute magnetic semiconductors (DMS). The nature of ferromagnetism, that occurs in p-type DMS with an increase in the transition metal content, is governed by the proposed kinematic exchange involving the kinetic energy gain of the heavy hole carriers caused by their hybridization with 3d electrons of impurities. The synthesis of DMS (In,Mn)Sb is proposed on the basis of hint at its T_C from kinematic mechanism. The effect of the dimensionality-driven T_C increase is derived for spintronics materials such as delta-doped DMS (DDMS) and DMS heterostructures. The state-of-the-art in the field of synthesis and research of “new” DMS with announced “high T_C” is also outlined with particular attention to chalcopyrite-based systems.