Thermal Expansion Characteristics In [001]-Oriented PMN-0.32PT Single Crystals

摘要

The thermal strain on cooling and heating process during -60 deg C to 200 deg C have been measured using DIL402C dilatometer for unpoled and poled [001]-oriented PMN-0.32PT single crystal. The thermal expansion anomalies were found within a wide temperature range around 0 deg C. Effects of poling electric field on thermal strain for single aystals were investigated. The obvious expansion and contraction were presented at rhombohedral - > tetragonal and tetragonal - > cubic phase transition for poled single crystal. However, thermal expansion responses at phase transition were weak for unpoled single crystal. The thermal expansion characteristics in [001]-oriented PMN-0.32PT single aystals are discussed together with data on dielectric properties.