Half-Metallic Ferromagnets, Spin Gapless Semiconductors, and Topological Semimetals Based on Heusler Alloys: Theory and Experiment

The paper presents a review of theoretical and experimental studies of the electronic structure and electronic and magnetic properties of various systems of Heusler alloys in the states of a half-metallic ferromagnet, spin gapless semiconductor, and topological semimetal. These substances have unusual magnetic and electronic characteristics and are highly sensitive to external effects, due to the presence of energy gaps and exotic excitations in them. Peculiarities of the behavior and evolution of the electronic structure and properties in each of these states and upon the transition between them are considered. The possibility of purposeful control of the properties of such materials opens up prospects for their practical application.