Magnetism of Nanosized “Nonmagnetic” Materials; the Role of Defects (Review)

This review analyzes experimental and theoretical works devoted to high-temperature ferromagnetism in nonmagnetic materials, the recently discovered phenomenon. The main attention is paid to nanoparticles of nonmagnetic materials, in which this phenomenon is most pronounced due to the features of the surface defect structure. In addition to the traditional theoretical models of band or state-localized defect-induced ferromagnetism and the nontrivial theory of giant orbital magnetism, the review discusses the ferron model, which is successfully used to fit the properties of advanced magnetic materials with phase separation.