Stability of the normal phase in a bounded current-carrying superconducting film

The two-phase equilibrium states of a current-carrying thin superconducting film in the case of convective heat transfer on the free surface are considered, and their stability is investigated in a first approximation. It is shown that of the two equilibrium states, the state with the normalphase region of larger size is stable. In the limiting case of an infinitely long film, the stable two-phase equilibrium state tends to a spatially uniform normal state, and the unstable state remains localized. In a definite range of values of the system parameters, the relaxation time of such a formation can be fairly long, and it should be regarded as a quasistable equilibrium state. Zh. Tekh. Fiz. 68, 71–77 (June 1998)