Figure 2. Magnetizations of the three typical samples.
(a) The magnetic field dependence of the magnetization of the three samples SFC (square symbols), S250 (filled circles) and S350 (triangle symbols). (b) The magnetization-hysteresis-loops of the sample S350 measured at temperatures from 2 to 28 K. A magnetization hysteresis can be observed up to 2 T even at 28 K, being close to Tc. (c) The magnetic field dependence of the critical current density calculated based on the Bean critical state model, although it may be invalid for this sample with phase separation. The purpose is to give a rough comparison between the present sample S350 and that of the FeAs-based 122 samples.