Enhancement of piezoelectric response in (100)/(001) oriented tetragonal Pb(Zr, Ti)O 3 films by controlling tetragonality and volume fraction of the (001) orientation

(100)/(001)-oriented 2 μ m-thick Pb(Ti, Zr)O 3 , films with the Zr/(Zr+Ti) ratio of 0.39 and 0.50 were prepared by metalorganic chemical vapor deposition. The volume fraction of (001)-oriented domain, Vc , was controlled by selecting the kinds of substrates with different thermal expansion coefficient. The effective piezoelectric constant increased up to 310 pm/V with decreasing the Vc and tetragonality (lattice parameter ratio of c axis to a axis) determined by the decrease of the Zr/(Zr+Ti) ratio. Observed large piezoelectric response was considered to be mainly contributed by the extrinsic effect, such as the 90 o domain switching. These experimental inputs suggest the new concept for enhancement of the piezoelectric properties.