1. Superconducting state of filled-skutterudite RPt4Ge12 (R= La, Pr):73Ge-NQR studies
- Author
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Fumiya Kanetake, Eugene E. Haller, K. M. Itoh, Hidekazu Mukuda, Yasuo Kitaoka, Ko-ichi Magishi, and Hitoshi Sugawara
- Subjects
Superconductivity ,Physics ,Condensed matter physics ,Band gap ,Spin–lattice relaxation ,Energy Engineering and Power Technology ,Fermi surface ,engineering.material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Superconductivity ,Quasiparticle ,engineering ,Condensed Matter::Strongly Correlated Electrons ,Skutterudite ,Electrical and Electronic Engineering ,Anisotropy ,Nuclear quadrupole resonance - Abstract
We report 73 Ge-NQR studies on filled-skutterudite superconductors LaPt 4 Ge 12 and PrPt 4 Ge 12 under zero external field. In PrPt 4 Ge 12 , the measurement of the nuclear spin-lattice relaxation rate 1/ T 1 has revealed a distinct coherence peak just below T c followed by an exponential decrease well below T c , evidencing that PrPt 4 Ge 12 is an s -wave superconductor with the isotropic gap in a weak-coupling regime. In LaPt 4 Ge 12 , the 1/ T 1 exhibits the exponential decrease well below T c , suggesting the isotropic s -wave superconductivity. Even though 73 Ge-NQR-1/ T 1 in LaPt 4 Ge 12 has been measured under zero field, its coherence peak was absent, which contrasts with the result in Pr-compound. This may point to a possible anisotropy in the Fermi surface and/or some damping effect of quasiparticles in association with electron–phonon interactions.
- Published
- 2010
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