Abstract
We report on the correlated investigation between macroscopic piezoelectric properties and the microscopic deformation of crystal structures of both epitaxial and polycrystalline Pb(Zr,Ti)O3 (PZT) thin films grown on MgO and Si substrates, respectively. We observed the reversible elongation and contraction of lattice parameter under an applied electric field using synchrotron X-ray diffraction. The effective piezoelectric coefficients were estimated from the relationship between electric field and field-induced strain, and compared with those characterized by the macroscopic cantilever method. The electric field dependences of the piezoelectric coefficients obtained from both characterization were in good agreement with each other. The results also revealed large and nonlinear piezoelectric properties for the polycrystalline PZT thin film. The comparative discussion in this study provides valuable insights of crystallographic contributions and opens the way to improve the piezoelectricity in thin-film based piezoelectric devices.
Highlights
Piezoelectric materials, such as lead zirconate titanate Pb(Zr,Ti)O3 (PZT) for example, provide the means to convert between mechanical and electrical energies that arise from direct and converse piezoelectric effects
To understand the crystallographic factors contributing to the macroscopic piezoelectric properties, we performed in-situ X-ray diffraction (XRD) measurements[18,19,20,21,22,23,24] on PZT thin films using a synchrotron radiation source
The Zr/Ti ratio was approximately 52/48, which is near the morphotropic phase boundary (MPB) composition
Summary
We prepared epitaxial PZT thin films on (001)Pt/MgO substrates and polycrystalline PZT thin films on (111) Pt/Ti/SiO2/Si substrates. We observed a small PZT 400 tetragonal peak in the XRD pattern, which confirms the constancy in the peak position and peak area ratios between 004 and 400 peaks (Supplementary Fig. S3(b,c)) This indicates an absence of a 90° domain rotation in the epitaxial PZT thin film. The effective piezoelectric coefficients (d33,f) for the epitaxial and polycrystalline PZT thin films were estimated from the relationship between electric field and field-induced strain. The electric field dependences of the piezoelectric coefficients attained from both in-situ XRD results and the cantilever method agree well each other Both evaluations indicate that the piezoelectric property of the polycrystalline PZT thin film was larger than that of the epitaxial PZT thin film. This study highlights the importance of comparative discussions to improve the piezoelectric properties of piezoelectric thin films for the application of novel piezoelectric MEMS devices
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have