Spatial variation in the magnetic properties of single crystal Nd123

Large Nd1+xBa2-xCu3Oy (Nd 123ss) single crystal cubes of side 3 mm were fabricated isothermally by the flux method. The crystals exhibited a T-c of 95 K with a sharp superconducting transition. One crystal was cut into small pieces, and its magnetic properties were measured to study the spatial distribution of the superconducting properties. It was found that although T-c values were almost constant, a small but significant intrinsic difference in the J(c)-B properties and irreversibility held was observed depending on the sample position. This suggests that the distribution of Nd-rich Nd123ss clusters are spatially different even within the same single crystal. Such differences may be caused by the time variation of Nd concentration in the liquid during crystal growth.