Spin Canting and Transverse Relaxation at Surfaces and in the Interior of Ferrimagnetic Particles

Analytical expressions for the magnetic energy and the spin-canting angles in some simple ferrimagnetic bulk and surface structures are presented. It is shown that the energy barriers separating different spin-canted states often will be very small. Therefore, the spin canting may be static only at very low temperatures and dynamic at higher temperatures. The calculations elucidate the field dependence of the canting angles, the high-field susceptibility of complex magnetic materials, the high-frequency susceptibility of diamagnetically substituted ferrites, and the apparently temperature-independent relaxation phenomena at very low temperatures.