Specific-heat measurements on Na0.35CoO2 · 1.3H2O show an evolution of the superconductivity, and its ultimate disappearance, with increasing sample age. An increase in pair breaking action, which occurs preferentially in an electron band with a small energy-gap, produces a shift in the relative contributions of two electron bands to the superconducting condensation. The similarity of the time scale for these changes to that recently reported for structural changes suggests a relation between the two effects and a basis for understanding the sample dependence of the properties of this material in general.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
- Pair breaking