Critical current density and flux pinning characteristics in melt-textured Y_0.6Er_0.4Ba₂Cu₃O_y superconductor

We prepared highly textured YBa₂Cu₃O_y and Y_0.6Er_0.4Ba₂Cu₃O_y 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 Jc estimated by the Bean's model decreases with the magnetic field according to a power law J_c ∝ 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. The reduction of the size of Y₂BaCuO₅ particles, magnetic pinning and stress-field pinning caused by the Er addition may be responsible for the enhancement of J_c and flux pinning.