0100503461

open access

Version of Record

Layer configuration-driven phase engineering of Sol-Gel epitaxial Pb(Zr,Ti)O₃ thin films for high piezoelectricity on silicon substrate

English (英語)

Acta Materialia

311

122162

Elsevier

2026-06-01

2026-04-06

In this study, we investigate piezoelectric behavior of sol-gel derived epitaxial Pb(Zr,Ti)O₃ (PZT) thin films with hetero-layered (HL) configurations on Si substrates. HLx/y films are fabricated by stacking two PZT layers with the same or different Zr/Ti ratios, where x and y indicate the Zr contents of the first and second layers, respectively, and this bilayer sequence is repeated throughout the film. We examine HL52/52 (equal to single-composition-deposited film, SCD52), HL60/45, and HL45/60, which share almost identical average compositions, to investigate how the stacking sequence affects film properties. Furthermore, in-situ bias-resolved reciprocal space mapping (RSM) is employed to elucidate the electric-field-induced structural responses associated with their piezoelectric behavior. We extend our discussion to films with various layer configurations, where they are classified into four structural types; α-, β-, γ-, and δ-PZT. The effective transverse piezoelectric coefficient, |e31,f|, is evaluated under both positive and negative unipolar oscillations. A clear correlation is found between the crystal structure and the built-in electric field (BIEF) direction, which significantly influences |e31,f|. Notably, the highest |e31,f| values are found near the morphotropic phase boundary (MPB): HL45/60 achieves 15.9 C m⁻² under negative unipolar oscillation, while HL60/45 reaches 13.5 C m⁻² under positive unipolar oscillation. These results demonstrate that by tailoring the layer configuration, the piezoelectric response of sol-gel derived epitaxial PZT thin films can be effectively optimized.

Si substrate

学術雑誌論文

This is an open access article under the Creative Commons Attribution 4.0 International license