Y. Feng et al., FISHTAIL EFFECT, MAGNETIC-PROPERTIES AND CRITICAL-CURRENT DENSITY OF GD-ADDED PMP YBCO, Physica. C, Superconductivity, 297(1-2), 1998, pp. 75-84
The magnetization curves of YBa2Cu3Oy and Y0.4Gd0.6Ba2Cu3Oy samples pr
epared by a powder melting process technique were measured with a supe
rconducting quantum interference device magnetometer at different temp
eratures. Fishtail effects are observed below 70 K with the H perpendi
cular to c configuration in the Gd-added sample, while no peak effect
is found in YBCO. The origin of the fishtail is discussed. It is found
that J(c) and flux pinning can be increased by the Gd addition. The m
agnitude of the improvement of J(c) increases with the magnetic field.
The reduction of the size of Y2BaCuO5 particles, stress-field pinning
and magnetic pinning induced by the substitution of Gd for Y may expl
ain the enhancement of J(c) and flux pinning. (C) 1998 Elsevier Scienc
e B.V.