Specific heat study of the Na0.3CoO2 · 1.3H2O superconductor: Influence of the complex chemistry

B. G. Ueland; P. Schiffer; R. E. Schaak; M. L. Foo; V. L. Miller; R. J. Cava

doi:10.1016/j.physc.2003.08.005

Specific heat study of the Na_0.3CoO₂ · 1.3H₂O superconductor: Influence of the complex chemistry

B. G. Ueland, P. Schiffer, R. E. Schaak, M. L. Foo, V. L. Miller, R. J. Cava

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

25 Scopus citations

Abstract

We report results of specific heat measurements on polycrystalline samples of the layered superconductor, Na_0.3CoO₂ · 1.3H₂O. The electronic contribution to the specific heat, γ, is found to be 12.2 mJ/mol K². The feature at the superconducting transition is rather sharp, becoming broad and strongly suppressed in an applied magnetic field. The data indicate a residual normal state electronic specific heat at low temperatures, implying that there is a sizable population of normal state electrons in the samples even below T_c. Inhomogeneity in the Na content, to which the superconducting state is exquisitely sensitive, appears to be the most likely explanation for these results. These results further indicate that special sample handling is required for an accurate characterization of the superconducting state in this material.

Original language	English (US)
Pages (from-to)	27-30
Number of pages	4
Journal	Physica C: Superconductivity and its applications
Volume	402
Issue number	1-2
DOIs	https://doi.org/10.1016/j.physc.2003.08.005
State	Published - Feb 1 2004
Externally published	Yes

All Science Journal Classification (ASJC) codes

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

Keywords

NaCoO · 1.3HO
Sodium cobalt oxyhydrate
Specific heat

Access to Document

10.1016/j.physc.2003.08.005

Cite this

@article{1b9a28090ccc4b98a21e41252255d031,

title = "Specific heat study of the Na0.3CoO2 · 1.3H2O superconductor: Influence of the complex chemistry",

abstract = "We report results of specific heat measurements on polycrystalline samples of the layered superconductor, Na0.3CoO2 · 1.3H2O. The electronic contribution to the specific heat, γ, is found to be 12.2 mJ/mol K2. The feature at the superconducting transition is rather sharp, becoming broad and strongly suppressed in an applied magnetic field. The data indicate a residual normal state electronic specific heat at low temperatures, implying that there is a sizable population of normal state electrons in the samples even below Tc. Inhomogeneity in the Na content, to which the superconducting state is exquisitely sensitive, appears to be the most likely explanation for these results. These results further indicate that special sample handling is required for an accurate characterization of the superconducting state in this material.",

keywords = "NaCoO · 1.3HO, Sodium cobalt oxyhydrate, Specific heat",

author = "Ueland, {B. G.} and P. Schiffer and Schaak, {R. E.} and Foo, {M. L.} and Miller, {V. L.} and Cava, {R. J.}",

note = "Funding Information: We gratefully acknowledge support from NSF grants DMR-0244254, DMR-0101318, DMR-0213706 and DOE grant DE-FG02-98-ER45706.",

year = "2004",

month = feb,

day = "1",

doi = "10.1016/j.physc.2003.08.005",

language = "English (US)",

volume = "402",

pages = "27--30",

journal = "Physica C: Superconductivity and its applications",

issn = "0921-4534",

publisher = "Elsevier B.V.",

number = "1-2",

}

TY - JOUR

T1 - Specific heat study of the Na0.3CoO2 · 1.3H2O superconductor

T2 - Influence of the complex chemistry

AU - Ueland, B. G.

AU - Schiffer, P.

AU - Schaak, R. E.

AU - Foo, M. L.

AU - Miller, V. L.

AU - Cava, R. J.

N1 - Funding Information: We gratefully acknowledge support from NSF grants DMR-0244254, DMR-0101318, DMR-0213706 and DOE grant DE-FG02-98-ER45706.

PY - 2004/2/1

Y1 - 2004/2/1

N2 - We report results of specific heat measurements on polycrystalline samples of the layered superconductor, Na0.3CoO2 · 1.3H2O. The electronic contribution to the specific heat, γ, is found to be 12.2 mJ/mol K2. The feature at the superconducting transition is rather sharp, becoming broad and strongly suppressed in an applied magnetic field. The data indicate a residual normal state electronic specific heat at low temperatures, implying that there is a sizable population of normal state electrons in the samples even below Tc. Inhomogeneity in the Na content, to which the superconducting state is exquisitely sensitive, appears to be the most likely explanation for these results. These results further indicate that special sample handling is required for an accurate characterization of the superconducting state in this material.

AB - We report results of specific heat measurements on polycrystalline samples of the layered superconductor, Na0.3CoO2 · 1.3H2O. The electronic contribution to the specific heat, γ, is found to be 12.2 mJ/mol K2. The feature at the superconducting transition is rather sharp, becoming broad and strongly suppressed in an applied magnetic field. The data indicate a residual normal state electronic specific heat at low temperatures, implying that there is a sizable population of normal state electrons in the samples even below Tc. Inhomogeneity in the Na content, to which the superconducting state is exquisitely sensitive, appears to be the most likely explanation for these results. These results further indicate that special sample handling is required for an accurate characterization of the superconducting state in this material.

KW - NaCoO · 1.3HO

KW - Sodium cobalt oxyhydrate

KW - Specific heat

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