Angular dependence of the relaxation times of 139La nuclei in La1 − x Sr x MnO3

Abstract

Relaxation of the magnetization of 139La nuclei is considered in lanthanum manganites, which are materials with anisotropic interactions of localized electronic spins, namely, the Dzyaloshinskiĭ-Moriya interactionand the interaction with a crystal field. Expressions are derived for the relaxation times of the longitudinal and transverse components of the nuclear magnetization, and the angular dependences of these relaxation times are found for the La0.95Sr0.05MnO3 compound. In contrast to electronic relaxation, the anisotropy of nuclear relaxation contains a contribution from the shift in the electron Zeeman frequency. The theoretically calculated numerical values of the nuclear relaxation times and their ratios correspond to the range of experimental values in the compounds studied. The results can be of importance for designing devices based on these materials and for further investigation.