Vortex-glass-type transition in YBa2Cu3O7- delta ceramics.

Abstract

We discuss a vortex-glass-type transition occurring in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ ceramics. It is suggested that the ``transition boundary'' ${\mathit{H}}_{\mathit{b}}$-${\mathit{T}}_{\mathit{b}}$ is a crossover line separating a nonlinear resistance state, associated with the motion of intergranular (Josephson) vortices, from a state which is characterized by a linear resistance caused by the motion of intragranular (Abrikosov) vortices. \textcopyright{} 1996 The American Physical Society.