Stress engineering for the design of morphotropic phase boundary in piezoelectric material

Alkoxide-derived lead zirconate titanate thin films having Zr/Ti = 50/50 to 60/40 compositions with different residual stress conditions were deposited on a Si wafer to clarify the effects of the residual stress on the morphotropic phase boundary shift. The residual stress condition was controlled to − 0.1 to − 0.9 GPa by the design of the buffer layer structure on the Si wafer. Results show that the maximum effective piezoelectric constant d33 was obtained at 58/42 composition under − 0.9 GPa compressive residual stress condition. Moreover, the MPB composition shifted linearly to Zr-rich phase with increasing compressive residual stress.