In-situ observation of ultrafast 90\xb0 domain switching under application of an electric field in (100)/(001)-oriented tetragonal epitaxial Pb(Zr0.4Ti0.6)O3 thin films

Yoshitaka Ehara,Osami Sakata,Takao Shimizu,Takahisa Shiraishi,Hiroshi Funakubo,Yasuhiko Imai,Ronald Maran,Tomoaki Yamada,Noriyuki Kanenko,Hiroki Tanaka,Shintaro Yasui,Takahiro Oikawa,Nagarajan Valanoor

doi:10.1038/s41598-017-09389-6

Abstract

Ferroelastic domain switching significantly affects piezoelectric properties in ferroelectric materials. The ferroelastic domain switching and the lattice deformation of both a-domains and c-domains under an applied electric field were investigated using in-situ synchrotron X-ray diffraction in conjunction with a high-speed pulse generator set up for epitaxial (100)/(001)-oriented tetragonal Pb(Zr0.4Ti0.6)O3 (PZT) films grown on (100)cSrRuO3//(100)KTaO3 substrates. The 004 peak (c-domain) position shifts to a lower 2θ angle, which demonstrates the elongation of the c-axis lattice parameter of the c-domain under an applied electric field. In contrast, the 400 peak (a-domain) shifts in the opposite direction (higher angle), thus indicating a decrease in the a-axis lattice parameter of the a-domain. 90° domain switching from (100) to (001) orientations (from a-domain to c-domain) was observed by a change in the intensities of the 400 and 004 diffraction peaks by applying a high-speed pulsed electric field 200 ns in width. This change also accompanied a tilt in the angles of each domain from the substrate surface normal direction. This behaviour proved that the 90° domain switched within 40 ns under a high-speed pulsed electric field. Direct observation of such high-speed switching opens the way to design piezo-MEMS devices for high-frequency operation.

Highlights

Significant feature and is required for the design of high-performance piezoelectric devises for MEMS applications
Lattice elongation and 180° domain wall motion were observed at sub-nanosecond timescales for (001)-oriented Pb(Zr1−xTix)O3 thin films[14, 15], and it has been reported that non180° ferroelastic domains can be switched by application of an electric field on the order of hundreds of nanoseconds[16, 17] in ferroelectric films
We investigated the change in lattice parameters and domain structure for 600-nm thick (100)/(001)-oriented epitaxial tetragonal Pb(Zr0.4Ti0.6)O3 films, which were subjected to an applied rectangular electric field pulses of 200-ns and rest time of 800 ns

Summary

Introduction

Significant feature and is required for the design of high-performance piezoelectric devises for MEMS applications. Lattice elongation and 180° domain wall motion were observed at sub-nanosecond timescales for (001)-oriented Pb(Zr1−xTix)O3 thin films[14, 15], and it has been reported that non180° ferroelastic domains can be switched by application of an electric field on the order of hundreds of nanoseconds[16, 17] in ferroelectric films It has not been clarified yet how fast does the 90° domain switching proceed - in particular, the relationship between the lattice elongation and geometrical domain structure deformation in tetragonal Pb(Zr1−xTix)O3 thin films has not been determined from a response speed point of view. We show that in contrast to conventionally accepted scenario of sluggish nature of ferroelastic domain switching as pointed out in ceramics[18], simultaneous lattice deformation (c-axis and a-axis) and ferroelastic domain switching (c-domain volume fraction and geometrical twin 90° domain structure) occurs on the order of sub-microseconds

Methods

Results

Conclusion