Investigation on the Thermal Stability of Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3 Single Crystals

摘要

Relaxor ferroelectric-based Pb(Mg_(1/3)Nb_(2/3))O_3_32PbTiO_3 (PMN-32PT) single crystal was prepared by using the vertical Bridgman method at the optimized condition and the thermal stability with temperature under different conditions was analyzed through the differential scanning calorimetry (DSC) and the thermal gravity analysis (TGA). The phases were identified by XRD. DSC/TGA results of the as-grown PMN-32PT crystal indicated that PMN-32PT crystals was stability before melting in the sealed conditions while kept instability in the temperature higher than 900℃ in the open system; the melting point of PMN-32PT was 1302.1℃ in sealed condition while reduced to 1282.9℃ in open system due to the evaporation of PbO and the transformation into pyrochlore phases.