Characteristic features of the formation of the resistive state in a Bi2Sr2CaCu2Oy crystal

The effect of a magnetic field H⊥(ab) on the transverse current-voltage characteristics (IVCs) of the mixed state of a single crystal of the layered superconductor Bi2Sr2CaCu2Oy (BSCCO) is investigated. It is established that in a wide range of temperatures and fields above the irreversibility line the initial part of the IVC is described by the law V∝Iγ with γ≃1. As the current increases further, this law is replaced by a section where V∝exp(I). It is established that the multivalued, multibranch characteristics, interpreted as a manifestation of an internal Josephson effect, do not change appreciably when the crystal passes into a state with nonzero linear resistance. The character of the dependence of the characteristic switching current on the first resistive branch, IJ(H,T), is determined.