Abstract
The temperature of spontaneous creation of vortex lines in Josephson coupled layered superconductors is obtained by taking into account the entropy contribution to the free energy due to thermal distortions. For Bi- and Ti-based high- superconductors and superlattices, the superconducting critical temperature lies noticeably below the mean-field transition temperature (-≊4 K or more). The contribution of thermal distortions to the free enery causes significant changes in the temperature and field dependences of magnetization below seen in Bi compounds.
- Received 3 March 1992
DOI:https://doi.org/10.1103/PhysRevLett.68.3773
©1992 American Physical Society