We investigated the relationship between the surface resistance (R s) and critical current density (Jc) of DyBa 2Cu3O7-δ (DyBCO) thin films in a dc magnetic field. The Rs of DyBCO films at 21.8 GHz was measured using a dielectric resonator method and the Jc was determined by magnetic measurement and Bean's model. A dc magnetic field of up to 5 T was applied along the c-axis of the films. The relationship between the Rs and J c of DyBCO thin films under a zero magnetic field was explained by the following equation, Rs = α × 107/J c, where a is a constant of 1.2, and the units of the Rs and Jc are ohm and A/m2, respectively. In addition, the Rs in dc magnetic fields up to 5 T were inversely proportional to the Jc. However, the parameter a, which was fitted from the R s - Jc characteristics in each magnetic field, increased slightly with an increase the magnitude of the applied field. These results indicate that the relationship between the Rs and Jc in a zero magnetic field may be a general property of HTS thin films and that the α in DyBCO thin films depends on the magnitude of the applied magnetic field.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering