Defect-induced lattice magnetism: Phenomenology of magnetic-field-stimulated defect reactions in nonmagnetic solids

摘要

We develop the phenomenology of magnetic-field-stimulated defect reactions in nonmagnetic solids based on the concept of defect-induced lattice magnetism (DILM) associated with a rise of spontaneous orbital currents in the elastic strain field produced by a defect. We present the hierarchy of all magnetic symmetry classes corresponding to the current structures with long-range or short-range orbital antiferromagnetic order depending on the perfect crystal symmetry and the symmetry of the defect-induced strain field. This strain field can result in a confinement of orbital currents and gives rise to size-quantized orbital magnon excitations. An external magnetic field leads to the splitting of magnon levels and causes the transitions between some of the intersecting Zeeman sublevels. The excitation of orbital magnon from the discrete size-quantized level into the continuous spectrum can be considered as the principal stage of magnetic field stimulated defect reactions. One can consider the DILM phenomenology as a contribution to a new field of solid state physics which could be termed the spin chemistry of solids.