In order to study the vortex-glass (VG) transition for conventional type-II superconductors, we have investigated the relation between the current density J and the resistivity p in the mixed state of aluminum films with different thickness and dirtiness. The aluminum films have the characteristics of lower Tc and longer coherence length in contrast with high-Tc superconductors. The J-ρ isotherms at various external magnetic fields have been analyzed by Fisher's VG theory. The data for the dirty thick film and dirty thin film can be well collapsed onto a single function according to the theories for three dimensional (3D) and two dimensional (2D) systems, respectively, with use of vortex-glass transition temperature, and reasonable values of critical exponent determined from the data analysis. However, for the thick clean film, there are some discrepancies between the experiment and 3D scaling theory; very narrow region of liquid phase and a small value of dynamic critical exponent. The reason for the narrow critical region has been discussed from a different viewpoint.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering