Scaling approaches to magnetization measurements of melt-textured (Y1-xPrx)Ba2Cu3O7-delta

Scaling approaches to magnetization measurements are explored on a set of melt-textured (Y1-xPrx)Ba2Cu3O7-delta samples with different Pr concentrations. When normalized with corresponding scaling parameters H-m, M(m), and J(m), respectively, magnetic hysteresis loops and related critical current densities for different temperatures from 4.5 to 75 K are all found to exhibit scaling behavior. It is shown that for low scaled field (h) region, this behavior can be described qualitatively well based on an extended critical-state model. The effective activation energy extracted from magnetic relaxation measurements can also be qualitatively described by a scaling relation within the framework of collective-pinning theory. In addition, Pr doping is found not to influence the scaling approaches themselves up to the highest level investigated in the present work. However, the scaled magnetic hysteresis loop width, critical current density, and effective activation energy are all increased by Pr doping, further suggesting the enhancement of flux pinning for our samples. Furthermore, experimental results and fitting parameters are discussed as well with respect to relevant scaling background models. (C) 1997 American Institute of Physics.