Physico-Chemical Analysis of Semiconductor-Ferromagnet Systems as a Basis of Synthesis of Magnetic-Granulated Spintronic Structures

Abstract

An analytical review devoted to the physicochemical principles of the synthesis of granular structures in semiconductor-ferromagnet systems is represented. In these systems, as semiconductors, compounds are A II B IV C V 2 , A III C V , A II 2 C V 3 and A II C V 2 and manganese compounds (MnP, MnAs and MnSb) as ferromagnets. It is shown that in magnetostransmitter devices magnetogranular structures are an alternative to superlattices, and the effects of GMR and TMR are also possible. Advantages of magneto-granular structures are considered, such as: less labor-intensive methods of production, milder requirements for the dimension of a ferromagnet and a nonmagnet, the possibility of forming a stable interface, soft requirements to the thickness of layers than in the case of superlattices, etc. It is shown that, due to the high mobility of charge carriers, the use of semiconductors as a matrix is more preferable than metals or dielectrics. The basic principles for the creation of granular structures with high values of magnetoresistance based on eutectic-type systems are formulated. During the crystallization of the eutectic, the simultaneous crystallization of all the phases that make up the eutectic takes place, leading to the formation of a specific fine-dispersed structure. The use of ultrahigh supersaturations leads to significant supercooling, which contributes to metastable crystallization. This causes a synergistic effect that stimulates nanostructuring, and promotes the creation of granular structures. The results of investigations of semiconductor-ferromagnet systems are presented and the possibility of obtaining magnetogranular structures with high magnetoresistance in them is shown.