{sup 63}Cu NMR probe of superconducting properties in HgBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+{delta}}: A possible reason for {ital T}{sub {ital c}}=133 K
- Department of Material Physics, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560 (Japan)
- Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaragi 305 (Japan)
Superconducting properties in HgBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+{delta}}, with a transition temperature of {ital T}{sub {ital c}}=133 K, have been investigated by measurements of the nuclear spin-lattice relaxation rate, {sup 63}(1/{ital T}{sub 1}). It has been found that the {ital T}{sub 1}{ital T}=const behavior, observed well below {ital T}{sub {ital c}}, arises from combined relaxation channels to vortex cores, as well as from a residual density of states (DOS), {ital N}{sub res}, at the Fermi level associated with the gapless superconductivity. From the value of {ital T}{sub 1}{ital T}=const in the latter channel, the DOS fraction normalized by its value at {ital T}{sub {ital c}},{ital N}{sub res}/{ital N}{sub {ital T}{sub {ital c}}}, has been deduced to be as small as {approximately}0.05. Based on the two-dimensional gapless {ital d}-wave model, the {ital T}{sub {ital c}} reduction rate, {Delta}{ital T}{sub {ital c}}/{ital T}{sub {ital c}0}, is estimated to be as small as 0.02 for {ital N}{sub res}/{ital N}{sub 0}{approximately}0.05. It is pointed out that these measures of the quality of HaBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+{delta}} explain why {ital T}{sub {ital c}} reaches such a high value. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 280220
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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