Self-similarity in the I-V characteristics of granular YBa2Cu3O7

The onset of dissipation in the I-V characteristics of granular YBa₂Cu₃O₇ shows clear evidence for a finite critical current. At currents above critical, dissipation in the weak links is only slightly field and temperature dependent. This self-similarity of the characteristics implies strongly that there is a true critical current, despite the random network nature of these materials. Also, it indicates that the dissipative behavior of the grain boundary weak links is almost field and temperature independent