We have examined the scaling behavior and the functional form of the I-V characteristics of YBa2Cu3O7-δ films at fields H from 0.001 to 6 T applied parallel to the c-axis. In all cases, the I-V curves obey the scaling law based on the second-order phase transition, and are fitted by V/I = R0 exp[-(I0/I)μ]. At high fields, the exponents v, z, and μ, are independent of H and are consistent with the prediction of the vortex-glass (VG) model. However, below ∼0.05 T, these exponents become H-dependent, which is indicative of the existence of another phase at low fields.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering