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

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.

The time-resolved hard X-ray diffraction endstation KMC-3 XPP at BESSY II

“…In these experiments the timing of the electrical excitation pulse and the detector is determined electronically, either by single photon counting modules or gated pixel detectors. Technically similar experiments on ferroelectric or piezoelectric activity have been conducted at other synchrotron radiation facilities (Lee et al, 2001;Do et al, 2008;Pramanick et al, 2009;Gorfman et al, 2015;Wallace et al, 2015;Davydok et al, 2016;Ehara et al, 2017); however, the sample environment at the KMC-3 XPP permits simultaneous characterization of the electric currents in the device for a complete operando characterization of structural and electric properties.…”

Identification of a coherent twin relationship from high-resolution reciprocal-space maps

“…It is mainly because the distribution of X-ray diffraction intensity from a multi-domain crystal may be as complex as the domain patterns themselves. Up until now, single-crystal X-ray diffraction was successfully applied for characterization of domains in epitaxial thin films (Ehara et al, 2017;Braun et al, 2018;von Helden et al, 2018;Lee et al, 2019Lee et al, , 2020Schmidbauer et al, 2020) where possible domain patterns are greatly limited by the constraints imposed by the substrate.…”

Time response demonstration of in situ lattice deformation under an applied electric field by synchrotron-based time-resolved X-ray diffraction in polar-axis-oriented epitaxial Pb(Zr,Ti)O3 film

“…[21][22][23][24] Some studies use the AC triangular field 25,26) or pulsed electric field, but single repetition is employed. 19,27,28) Thus, the in situ crystal analysis over a broad frequency range is scarcely reported despite its importance and interest, but it significantly helps us to understand the frequency dependence of the macroscopic piezoelectric response.…”

“…Therefore, it is essential and interesting to examine the frequency dependence of each component for piezoresponse. 19,20) Previous studies have succeeded in decomposing the piezoelectric contribution by in situ X-ray diffraction (XRD) measurement by applying an electric field and estimated the quantitative contribution of each piezoelectric component to the total piezoelectric response. This XRD measurement under an applied electric field is a powerful technique because it enables us to observe the crystal structure change directly under an applied electric field.…”