We demonstrate experimentally the existence of a continuous phase transition between a normal and a true superconducting phase (with zero linear resistivity) in epitaxial films of Y-Ba-Cu-O in strong magnetic fields fields, H≫${\mathrm{H}}_{\mathrm{c}1}$. The nonlinear I-V curves show scaling behavior near the transition and the relevant critical exponents are extracted. These exponents are consistent with values expected for freezing into a superconducting vortex-glass phase.

• Received 7 June 1989

DOI:https://doi.org/10.1103/PhysRevLett.63.1511

This article appears in the following collection:

Heating up of Superconductors

This collection marks the 30th anniversary of the discovery of high-temperature superconductors. The papers selected highlight some of the advances that have been made to date, both in understanding why these compounds behave in the way they do, and in utilizing them in applications.