MAGNETIC PHASE-DIAGRAM OF A SINGLE-CRYSTAL OF THE ELECTRON-DOPED HIGHT-C SUPERCONDUCTOR PR1.85CE0.15CUO4-Y

Magnetization measurements were performed on a Pr1.85Ce0.15CuO4-y sing le crystal with T-c approximate to 22.5 K in magnetic fields H applied parallel to the tetragonal c-axis (H parallel to c). A broad peak in the magnetization curves was observed that may be associated with a 2D -3D crossover in the vortex lattice at a temperature independent cross over field H-cr approximate to 230 Oe. The irreversibility line and lo wer critical field for H parallel to c were also estimated.