Reaction of platinum crucible and melt during PMN-PT crystal growth

PMN-PT crystals have been of considerable interest in recent years due to their excellent ferroelectric, piezoelectric, photoelectric properties and promising applications in various electric and electric–optical devices. However, the crucible leakage is usually a fetal limitation during preparation of the crystal. In this work, the PMN-PT crystals were prepared by Bridgman-accelerated crucible rotation technique (ACRT) method. The morphologies of the bottom surface of the PMN-PT crystal and the inner surface of the platinum crucible, in which the crystal grew, were examined by scanning electronic microscope (JSM-840). The local composition was analyzed by EDAX spectrometer attached to the scanning unit. Investigated results indicated that there are evident reaction between the platinum crucible and PbO–MgO–Nb2O5–TiO2 melt during PMN-PT crystal growth, which is the main cause of crucible leakage. Another cause of the crucible leakage is due to the unequally distorted platinum grain boundary.