We have performed nuclear quadrupole resonance (NQR) experiments on 47Ti nuclei in Dy2Ti2O7 in the temperature range 70 -- 300 K in order to investigate the dynamics of 4f electrons with strong Ising anisotropy. A significant change of the NQR frequency with temperature was attributed to the variation of the quadrupole moment of Dy 4f electrons. A quantitative account was given by the mean field analysis of the quadrupole-quadrupole (Q-Q) interaction in the presence of the crystalline-electric-field splitting. The magnitude and the temperature dependence of the nuclear spin-lattice relaxation rate was analyzed, including both the spin-spin and the Q-Q interactions. The results indicate that these two types of interaction contribute almost equally to the fluctuation of Dy magnetic moments.
@article{arxiv.0804.1413,
title = {High-temperature spin relaxation process in Dy$_2$Ti$_2$O$_7$ probed by $^{47}$Ti-NQR},
author = {K. Kitagawa and R. Higashinaka and K. Ishida and Y. Maeno and M. Takigawa},
journal= {arXiv preprint arXiv:0804.1413},
year = {2008}
}
Comments
8 pages, 6 figures, 1 table, accepted for publication in Phys. Rev. B