Evaluation of PZNT ferroelectric crystals grown by different methods

Relaxor ferroelectric (1-x)Pb(Zn1/3Nb2/3)O-3-xPbTiO(3)(PZNT) crystals were grown from PZNT-PbO high temperature solution by flux Bridgman, bottom seeded solution growth (BSSG) and gas-cooling methods. PZNT wafers cutting from flux Bridgman and BSSG-grown crystals were homogenous while serious inclusions were observed in PZNT wafers grown by the gas-cooling method. The < 001 >-oriented PZNT crystals exhibited nearly the same dielectric/piezoelectric properties whatever the growth methods. However, the mechanical properties, such as Vickers' Microhardness Hv and fracture toughness Kc of the crystal grown by gas-cooling method were much inferior. It was suggested that BSSG method is a potential approach for growing large-size and high-quality PZNT crystals.