Electric-field and stress effects on depoling and overpoling phenomena in [001]-poled transverse mode pb(zn1/3nb2/3)o3-(6-7)%pbtio3 single crystal of [110] length cut

摘要

Solid-solution Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZNPT) single crystals, touted as next-generation piezoelectric materials, have been studied extensively in the past decade. This work addresses the advantages and limitations of transducers made of transverse mode PZN-(6-7)%PT single crystals of [110]L X [001]T(P) cut. This cut exhibits superior electromechanical properties, with k31 Ȥ8; 0.85 and d31 Ȥ8;-1450 pC/N, and an extremely high d31/ SE11 value of >35 C/m2. It also has relatively high overpoling, i.e., rhombohedralto- tetragonal phase transformation, field of Ȥ8;2 kV/mm. This overpoling field further decreases with increase in axial compressive stress. Despite these good attributes, this crystal cut has a low depoling field of ʧD; 0.3 kV/mm, a result of low coercive fields of [001]-poled relaxor-based single crystals, which decreases further with increasing axial compressive stress, limiting its bipolar drive capability. The axial compressive stress required to cause overpoling via rhombohedral-to-tetragonal phase transformation of relevant domain variants in the crystal is found to be >90 MPa. In contrast, this crystal cut depolarizes at comparatively low axial tensile stress of Ȥ8;15 MPa, the magnitude of which is not significantly affected by the moderate forward field applied.