Role of Mn Doping on the Electromechanical Properties of 001 Domain Engineered Single crystals

摘要

We studied the influence of Mn doping on electromechanical properties of PZN-xPT with x = 7% and 9%. Single crystals oriented along the [111], [011] and [001] directions were poled by a "field cooling" process with an applied electric field of 1 kV/cm. It is shown that Mn doping has a significant influence on the single domain crystals in both cases. It modifies the phase symmetry of single domain PZN-7PT from orthorhombic to rhombohedral. It reduces permittivity perpendicular to polarization direction of single domain PZN-9PT by about 40%. This change in the properties of the bulk material is the main cause for the decrease of permittivity observed in [001] poled PZN-9PT crystals. Further effects of doping on the properties of [001] domain engineered crystals are a decrease of the piezoelectric coefficient, a hardening of the material and an increase of the mechanical quality factor.