Temperature Dependence of Nuclear Magnetic Resonance and Spin-Lattice Relaxation Time of23Na in a NaMnCl3 Single Crystal

Abstract

The temperature dependence of 23Na (I = 3/2) nuclear magnetic resonance in a NaMnCl3 crystal grown by the Czochralski method has been investigated by employing a Bruker FT NMR spectrometer. From the experimental data, the quadrupole coupling constant and asymmetry parameter are determined in the temperature range of 140 to 380 K. The principal z-axis of the EFG tensor of 23Na, the largest component, is parallel to the crystallographic c-axis. The quadrupole coupling constant of 23Na is found to be linearly increasing as the temperature increases. We have discussed the transferred hyperfine interaction due to the transfer of spin density from the Mn2+ ion to the Na+ ion in a NaMnCl3 single crystal. In addition, the temperature dependence of the relaxation time T—11 could be fitted by the approximation T—11 = {4.88T — 228.15} (s—1). Therefore, we conclude that the dominant contribution to the relaxation rate is explained by the direct process of scattering with a single phonon.