Acoustic emission study of phase transitions and polar nanoregions in relaxor-based systems: Application to the PbZn_(1/3)Nb_(2/3)O_3 family of single crystals

摘要

The restored strain energy in PbZn_(1/3)Nb_(2/3)O_3 (PZN) and 9 % PbTiO_3-doped PZN (PZN-9%PT) relaxor crystals has been studied by means of acoustic emission (AE). Two types of AE activity signals have been recorded: (ⅰ) related to temperature- or electric-field-induced macroscopic phase transitions and (ⅱ) associated with formation/disappearance of intrinsic polar nanoregions. Monitoring of AE under varying [001] electric fields has allowed a unique in situ observation of a low-field (1 kV/cm) irreversible orthorhombic-to-M_C phase transition within the morphotropic phase boundary region of PZN-9%PT.