Pyromagnetic effect in ferrimagnets with a 'weak' sublattice

The temperature dependence of the residual and spontaneous magnetization in ferrites with a 'weak' sublattice may be taken as evidence for the pyromagnetic effect — a magnetic analog of the pyroelectric effect — in which the magnetization of a sample increases on cooling in the absence of an external magnetic field. A confirmation of this has been provided by the observation of a thermodynamically inverse phenomenon, the linear magnetocaloric effect, in such ferrites. These effects are due to the unidirectional exchange anisotropy characteristic of ferrimagnets with a weak sublattice.