Critical current density and flux pinning characteristics in melt-texturedY0.6Er0.4Ba2Cu3Oy superconductor

We prepared highly textured YBa2Cu3Oy and Y0.6Er0.4Ba2Cu3Oy bulk samples by a powder melting process method under the same conditions and studied the magnetic properties and flux pinning characteristics. It is found that the J(c) estimated by the Bean's model decreases with the magnetic field accord ing to a power law J(c) proportional to B-n (n < 0.55), suggesting that J(c ) values of these materials are controlled by the flux pinning rather than weak links. Also, J(c) and flux pinning are improved by the Er addition. Th e reduction of the size of Y2BaCuO5 particles, magnetic pinning and stress- field pinning caused by the Er addition may be responsible for the enhancem ent of J(c) and flux pinning.