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.
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U2 - 10.1016/j.physc.2003.09.066
DO - 10.1016/j.physc.2003.09.066
M3 - Article
AN - SCOPUS:0348231704
VL - 402
SP - 106
EP - 113
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-2
ER -