Thermodynamic properties in the normal and superconducting states of Na xCoO 2 · yH 2O powder measured by heat capacity experiments

B. Lorenz; J. Cmaidalka; R. L. Meng; C. W. Chu

doi:10.1016/j.physc.2003.09.066

Thermodynamic properties in the normal and superconducting states of Na _xCoO ₂ · _yH ₂O powder measured by heat capacity experiments

B. Lorenz, J. Cmaidalka, R. L. Meng, C. W. Chu

Executive Vice President

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

25 Citations (Scopus)

Abstract

The heat capacity of superconducting Na _xCoO ₂· _yH ₂O was measured and the data are discussed based on two different models: The BCS theory and a model including the effects of line nodes in the superconducting gap function. The electronic heat capacity is separated from the lattice contribution in a thermodynamically consistent way maintaining the entropy balance of superconducting and normal states at the critical temperature. It is shown that for a fully gapped superconductor the data can only be explained by a reduced (≈50%) superconducting volume fraction. The data are compatible with 100% superconductivity in the case where line nodes are present in the superconducting gap function.

Original language	English
Pages (from-to)	106-113
Number of pages	8
Journal	Physica C: Superconductivity and its applications
Volume	402
Issue number	1-2
DOIs	https://doi.org/10.1016/j.physc.2003.09.066
Publication status	Published - 2004 Feb 1

All Science Journal Classification (ASJC) codes

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

Access to Document

10.1016/j.physc.2003.09.066

Cite this

@article{06b08ac327b943bfac932a359a67d4d9,

title = "Thermodynamic properties in the normal and superconducting states of Na xCoO 2 · yH 2O powder measured by heat capacity experiments",

abstract = "The heat capacity of superconducting Na xCoO 2· yH 2O was measured and the data are discussed based on two different models: The BCS theory and a model including the effects of line nodes in the superconducting gap function. The electronic heat capacity is separated from the lattice contribution in a thermodynamically consistent way maintaining the entropy balance of superconducting and normal states at the critical temperature. It is shown that for a fully gapped superconductor the data can only be explained by a reduced (≈50%) superconducting volume fraction. The data are compatible with 100% superconductivity in the case where line nodes are present in the superconducting gap function.",

author = "B. Lorenz and J. Cmaidalka and Meng, {R. L.} and Chu, {C. W.}",

note = "Funding Information: This work is supported in part by NSF Grant no. DMR-9804325, the T.L.L. Temple Foundation, the J.J. and R. Moores Endowment, and the State of Texas through the TCSAM and at LBNL by the Director, Office of Energy Research, Office of Basic Energy Sciences, Division of Materials Sciences of the US Department of Energy under Contract no. DE-AC03-76SF00098.",

year = "2004",

month = feb,

day = "1",

doi = "10.1016/j.physc.2003.09.066",

language = "English",

volume = "402",

pages = "106--113",

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

issn = "0921-4534",

publisher = "Elsevier BV",

number = "1-2",

}

TY - JOUR

T1 - Thermodynamic properties in the normal and superconducting states of Na xCoO 2 · yH 2O powder measured by heat capacity experiments

AU - Lorenz, B.

AU - Cmaidalka, J.

AU - Meng, R. L.

AU - Chu, C. W.

N1 - Funding Information: This work is supported in part by NSF Grant no. DMR-9804325, the T.L.L. Temple Foundation, the J.J. and R. Moores Endowment, and the State of Texas through the TCSAM and at LBNL by the Director, Office of Energy Research, Office of Basic Energy Sciences, Division of Materials Sciences of the US Department of Energy under Contract no. DE-AC03-76SF00098.

PY - 2004/2/1

Y1 - 2004/2/1

N2 - The heat capacity of superconducting Na xCoO 2· yH 2O was measured and the data are discussed based on two different models: The BCS theory and a model including the effects of line nodes in the superconducting gap function. The electronic heat capacity is separated from the lattice contribution in a thermodynamically consistent way maintaining the entropy balance of superconducting and normal states at the critical temperature. It is shown that for a fully gapped superconductor the data can only be explained by a reduced (≈50%) superconducting volume fraction. The data are compatible with 100% superconductivity in the case where line nodes are present in the superconducting gap function.

AB - The heat capacity of superconducting Na xCoO 2· yH 2O was measured and the data are discussed based on two different models: The BCS theory and a model including the effects of line nodes in the superconducting gap function. The electronic heat capacity is separated from the lattice contribution in a thermodynamically consistent way maintaining the entropy balance of superconducting and normal states at the critical temperature. It is shown that for a fully gapped superconductor the data can only be explained by a reduced (≈50%) superconducting volume fraction. The data are compatible with 100% superconductivity in the case where line nodes are present in the superconducting gap function.

UR - http://www.scopus.com/inward/record.url?scp=0348231704&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0348231704&partnerID=8YFLogxK

U2 - 10.1016/j.physc.2003.09.066

DO - 10.1016/j.physc.2003.09.066

M3 - Article

AN - SCOPUS:0348231704

SN - 0921-4534

VL - 402

SP - 106

EP - 113

JO - Physica C: Superconductivity and its applications

JF - Physica C: Superconductivity and its applications

IS - 1-2

ER -

Thermodynamic properties in the normal and superconducting states of Na _xCoO ₂ · _yH ₂O powder measured by heat capacity experiments

Abstract

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this