May, 2011
As-NMR/NQR study of pressure-induced superconductivity in CaFe2As2
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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- Volume
- 72
- Number
- 5
- First page
- 501
- Last page
- 504
- Language
- English
- Publishing type
- Research paper (scientific journal)
- DOI
- 10.1016/j.jpcs.2010.10.010
- Publisher
- PERGAMON-ELSEVIER SCIENCE LTD
As-75-zero-field nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements are performed on CaFe2As2 under pressure. At P=4.7 and 10.8 kbar, the temperature dependence of nuclear-spin-lattice relaxation rate (1/T-1) measured at tetragonal phase show no coherence peak just below T-c and decrease with decreasing temperature. The superconductivity is of gapless at P=4.7 kbar but evolves to multiple gaps at P=10.8 kbar. We find that the superconductivity appears near a quantum critical point. Both electron correlation and superconductivity disappear in the collapsed tetragonal phase. A systematic study under pressure indicates that electron correlations play a vital role in forming Cooper pairs in this compound. (C) 2010 Elsevier Ltd. All rights reserved.
- Link information
- ID information
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- DOI : 10.1016/j.jpcs.2010.10.010
- ISSN : 0022-3697
- Web of Science ID : WOS:000291518100049