Effects of contact resistance between superconductor and stabilizer on stability in oxide-superconducting composites

The stability of superconducting composites of an oxide superconductor and a stabilizer with high electrical conductivity was studied theoretically in relation to contact resistance between the superconductor and the metal. The stability parameter of the minimum propagation zone (MPZ) was evaluated from an equilibrium distribution of temperature along the wire. Additional heat generation due to the contact resistance was induced around the normal zone and reduced the size of the MPZ. The relationship between the contact resistance and the stability was calculated numerically by a heat balance equation for the composite. A stability criterion for external disturbances was proposed as the condition for the size of the MPZ asymptotically approaching zero. This stability condition gives an upper limit on the current density as a function of the contact resistance