On the existence of multistable resistive states at current injection into a high-temperature superconductor
V. R. Romanovskii;
The stability of resistive states in Bi2223 superconductor without a stabilizing matrix and with decreasing temperature dependence of the resistive-transition index of its I–V characteristic is studied in a steady-state approximation. Analysis is carried out for a superconductor placed in a constant magnetic field when it is slightly cooled by a coolant with a varying working temperature. It is shown that additional stable resistive states may arise in the case of high electric fields and overheats. These (multistable) states are characterized by stable steps in the electric field intensity and temperature, which do not transfer the supercon-ductor into the normal state. The multistable resistive states may be related to the nontrivial variation of the superconductor’s differential resistance. In this case, a decrease in the critical current density of the super-conductor and its related decrease in the China magnets resistive-transition index of the I–V characteristic with increasing temperature play the key role in the formation of these states. Their presence should be taken into consideration both in analyzing the stable conditions of high-temperature superconductors and in describing processes observed in superconducting magnets when they pass into the normal state.http://www.chinamagnets.biz
