Investigation of exchange interactions in aluminum lithium ferrites

The temperature dependence and the curie points of compounds of alu­minum lithium ferrite possessing a spinel structure have been measured. Using the method of Rado and Folen [l] the molecular field coefficients α, β and n are determined for four compositions. It was established that with the introduction of Al^{3+} into the lithium ferrite the BB interaction becomes stronger than the AA interaction. From the data concerning the coefficients it is concluded that in ferrites possessing temperature compensation of the magnetic moments of the sublattices [curve of 𝜎s(T)of type N), the exchange interaction within each sublattice plays a significant role.