Microstructures of an MTG YBa2Cu3Oysuperconductor

Abstract
Microstructures of a YBa2Cu3Oy superconductor having a Jc value of 23800 A cm-2 at 77 K in a 2 T magnetic field, prepared by the MTG technique, were studied by TEM. The grains of the 123 phase in the superconductor preferentially align with mutually parallel a-b conductive planes. The granular Y2BaCuO5 and CuO are dispersed in the 123 phase and many dislocations, dislocation loops and stacking faults exist in the 123 phase. These crystal defects may be the main flux pinning centres and may play an important role in the increase of the Jc value in a magnetic field.