WhenNdBa2Cu3O7−&dgr;(Nd123) is melt-textured in low oxygen partial pressure(Po2)and subsequently annealed in oxygen to produce the superconducting phase, there is a considerable enhancement of flux pinning compared to Y123. This enhancement is accompanied by a precipitation mechanism due to a change of the solubility limits ofNd1+xBa2−xCu3O7−&dgr;between the high temperature lowPo2conditions used in melt-textured growth and the low temperature oxygen annealing. Transmission electron microscopy reveals a coherent intermediate precipitate structure with a composition ofBaCuO2and a high density of dislocations. We believe these defects are responsible for the strong flux pinning in this material. ©1997 American Institute of Physics.