Transverse piezoelectric properties of {110}-oriented PLZT thin films

Abstract

Preferentially {110}-oriented thin films of lead lanthanum zirconate titanate, (Pb, La) (Zr, Ti)O₃ [PLZT] having compositions (7/65/35), (7/60/40) and (7/56/44) across the morphotropic phase boundary with a thickness of 1.5µm were prepared on platinised silicon substrates (111) Pt/Ti/SiO₂/Si by sol-gel spin coating technique. The crystallographic orientation and crystalline phases were analysed by X-ray diffraction and Raman spectroscopy respectively. The dependence of the transverse piezoelectric coefficient, $e_{31,f}$ of the PLZT thin films on their composition and texture have been investigated. PLZT (7/60/40) thin films having a higher tetragonal content was found to exhibit optimum piezoelectric characteristics. By combining the results obtained from the dielectric and polarisation-electric field (P-E) studies, the domain switching mechanism responsible for $e_{31,f}\mathrm{ }$have been established.

Keywords:

• Piezoelectricity
• thin films
• domain structure
• crystallographic orientation

Funding

One of the authors, Laxmi Priya S would like to acknowledge UGC for the Senior Research Fellowship granted. This work was supported by Japan Science and Technology Agency (JST) A-STEP (AS272S002a) and CREST (JPMJCR16Q4).