Superconducting state of filled-skutterudite RPt4Ge12 (R = La, Pr): 73Ge-NQR studies

F. Kanetake; H. Mukuda; Y. Kitaoka; H. Sugawara; K. Magishi; K. M. Itoh; E. E. Haller

doi:10.1016/j.physc.2009.11.127

Superconducting state of filled-skutterudite RPt₄Ge₁₂ (R = La, Pr): ⁷³Ge-NQR studies

F. Kanetake, H. Mukuda, Y. Kitaoka, H. Sugawara, K. Magishi, K. M. Itoh, E. E. Haller

Department of Applied Physics and Physico-Informatics

Research output: Contribution to journal › Article › peer-review

12 Citations (Scopus)

Abstract

We report ⁷³Ge-NQR studies on filled-skutterudite superconductors LaPt₄Ge₁₂ and PrPt₄Ge ₁₂ under zero external field. In PrPt₄Ge₁₂, the measurement of the nuclear spin-lattice relaxation rate 1/T₁ has revealed a distinct coherence peak just below T_c followed by an exponential decrease well below T_c, evidencing that PrPt ₄Ge₁₂ is an s-wave superconductor with the isotropic gap in a weak-coupling regime. In LaPt₄Ge₁₂, the 1/T ₁ exhibits the exponential decrease well below T_c, suggesting the isotropic s-wave superconductivity. Even though ⁷³Ge-NQR-1/T₁ in LaPt₄Ge₁₂ 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.

Original language	English
Pages (from-to)	S703-S704
Journal	Physica C: Superconductivity and its applications
Volume	470
Issue number	SUPPL.1
DOIs	https://doi.org/10.1016/j.physc.2009.11.127
Publication status	Published - 2010 Dec

Keywords

Filled-skutterudite
NMR
NQR
RPtGe
Superconductivity

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Energy Engineering and Power Technology
Electrical and Electronic Engineering

Access to Document

10.1016/j.physc.2009.11.127

Cite this

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title = "Superconducting state of filled-skutterudite RPt4Ge12 (R = La, Pr): 73Ge-NQR studies",

abstract = "We report 73Ge-NQR studies on filled-skutterudite superconductors LaPt4Ge12 and PrPt4Ge 12 under zero external field. In PrPt4Ge12, the measurement of the nuclear spin-lattice relaxation rate 1/T1 has revealed a distinct coherence peak just below Tc followed by an exponential decrease well below Tc, evidencing that PrPt 4Ge12 is an s-wave superconductor with the isotropic gap in a weak-coupling regime. In LaPt4Ge12, the 1/T 1 exhibits the exponential decrease well below Tc, suggesting the isotropic s-wave superconductivity. Even though 73Ge-NQR-1/T1 in LaPt4Ge12 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.",

keywords = "Filled-skutterudite, NMR, NQR, RPtGe, Superconductivity",

author = "F. Kanetake and H. Mukuda and Y. Kitaoka and H. Sugawara and K. Magishi and Itoh, {K. M.} and Haller, {E. E.}",

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T2 - 73Ge-NQR studies

AU - Kanetake, F.

AU - Mukuda, H.

AU - Kitaoka, Y.

AU - Sugawara, H.

AU - Magishi, K.

AU - Itoh, K. M.

AU - Haller, E. E.

PY - 2010/12

Y1 - 2010/12

N2 - We report 73Ge-NQR studies on filled-skutterudite superconductors LaPt4Ge12 and PrPt4Ge 12 under zero external field. In PrPt4Ge12, the measurement of the nuclear spin-lattice relaxation rate 1/T1 has revealed a distinct coherence peak just below Tc followed by an exponential decrease well below Tc, evidencing that PrPt 4Ge12 is an s-wave superconductor with the isotropic gap in a weak-coupling regime. In LaPt4Ge12, the 1/T 1 exhibits the exponential decrease well below Tc, suggesting the isotropic s-wave superconductivity. Even though 73Ge-NQR-1/T1 in LaPt4Ge12 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.

AB - We report 73Ge-NQR studies on filled-skutterudite superconductors LaPt4Ge12 and PrPt4Ge 12 under zero external field. In PrPt4Ge12, the measurement of the nuclear spin-lattice relaxation rate 1/T1 has revealed a distinct coherence peak just below Tc followed by an exponential decrease well below Tc, evidencing that PrPt 4Ge12 is an s-wave superconductor with the isotropic gap in a weak-coupling regime. In LaPt4Ge12, the 1/T 1 exhibits the exponential decrease well below Tc, suggesting the isotropic s-wave superconductivity. Even though 73Ge-NQR-1/T1 in LaPt4Ge12 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.

KW - Filled-skutterudite

KW - NMR

KW - NQR

KW - RPtGe

KW - Superconductivity

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