Shift in nuclear magnetic resonance. I. Above the Neel temperature

Abstract

A new shift in the nuclear magnetic resonance frequency of ligand nuclei in antiferromagnets above the Neel temperature is obtained as a direct consequence of inclusion of phonon-induced effects in the transferred hyperfine coupling. The shift has two parts, one of which has the same temperature dependence as the usual paramagnetic susceptibility chi (T). The other part at low temperature depends on T4 chi (T). Both the experimental and the theoretical evidence is produced for the 19F nuclei in MnF2.