Nuclear Magnetic Resonance measurements have been carried out in type VIII Ba8Ga16Sn30 (α-BGS) and type I Ba 8Ga16Sn30 (3-BGS) clathrates having caged structure. We have observed Sn-and Ga-NMR spectra for both clathrates. Characteristic Sn-NMR line profiles for both clathrates can be explained by taking account of the crystallographic sites in the framework of cages. We have also measured nuclear spin-spin relaxation rate 1/T2 in α-BGS. 1/T2 weakly depends temperature, but it is drastically suppressed with increasing resonance frequency. These results strongly suggest that the guest Ba ions vibrates at on-center location with characteristic correlation time of ≈ 10-8 s.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)