Magnetic field dependence of the pinning effect in -doped ceramic superconductor

Y Ba2Cu3O7−δ(Y BCO)+BaZrO3 composites were prepared through the solid-state route, employing nitrate precursors of BaZrO3 (BZO), yielding submicron particles. Invoking Bean’s critical state model, an enhancement of J c in composite samples in the presence of a magnetic field at a temperature ( T ) of 40 K has been observed. The resistive broadening in the tail part is suggested to be associated with the link between the grains and to be extremely sensitive to the magnetic field. It is assumed that the global zero-resistance state in the T c 0 region of high-temperature superconductivity (HTSC) is governed by the excitations in the weak-link network.