Substrate effects on intrinsic thermal stability and quench recovery for thin-film superconductors

Abstract

Two-dimensional conjugate film/substrate conduction equations considering an instantaneous release of energy in the form of a line source, anisotropic thermal conductivity of the film, and Joule heat are employed to investigate substrate effects on the intrinsic thermal stability and quenching recovery of thin-film superconductors. The results show that substrate effects exert significant influences on thermal stability of superconductors, because the higher thermal conductivity of substrates than those of films can cause heat feedback from the substrates. Both critical current densities related to intrinsic stability and recovery are calculated for different ratios of thermal conductivity and thickness of film to substrate, substrate materials, superconductors, Blot numbers, and operating temperatures. (C) 1996 Elsevier Science Limited