Abstract
We report experimental results of nuclear magnetic resonance (NMR) at the La site and nuclear quadrupole resonance (NQR) at the Sb site in the filled skutterudite . We found that the nuclear spin-lattice relaxation rate divided by temperature at the La site exhibits a different temperature dependence from that at the Sb site. Although at the Sb site is explained by the Korringa mechanism, at the La site exhibits a broad maximum around , showing the presence of an additional contribution at the La site. The additional low-lying excitations observed at the La site can be understood with the relaxation from anharmonic phonons due to the rattling motion of the La atoms.
- Received 5 November 2007
DOI:https://doi.org/10.1103/PhysRevB.77.041101
©2008 American Physical Society