The authors have measured the resistance of a polycrystalline sample of Tl-Ba-Ca-Cu-O as a function of temperature and magnetic field. Above T c, they see no systematic change in resistance as a magnetic field is applied. The deviation from linearity (onset of paraconductivity) in the resistivity transition Tc has been analysed in terms of fluctuations. Application of a magnetic field has only a small effect on the paraconductivity. Below Tc, the resistivity transition has an activated behaviour with activation energies varying from 1 eV at 0 T to 40 meV at 19 T. This behaviour may be explained within the framework of Anderson's theory of thermally activated flux motion.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Condensed Matter Physics
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry