Determining fundamental properties from diffraction: Electric field induced strain and piezoelectric coefficient

Abstract

Neutron powder diffraction was used in operando to determine the macroscopic strain and piezoelectric coefficient as a function of applied electric field in a technically relevant actuator material. We were able to individually investigate the two coexisting phases in the material and reveal the origin of maximized strain at phase boundaries. Insight into the strain mechanisms with unprecedented detail gives evidence that, on average, the classic inverse piezoelectric effect does not apply for polycrystalline materials.

Electric-Field-Induced Phase Transformation and Frequency-Dependent Behavior of Bismuth Sodium Titanate–Barium Titanate

“…The third reflection of the 200 C triplet at 2θ = 6.05 • , between the two tetragonal split reflections, indicates the occurrence of a pseudo-cubic second phase [33,52]. A similar behavior was observed for the relaxor system BNT-25ST, in which a second phase was also present [53].…”

“…One effect is supposedly owed to kinetics. It was shown for PZT that for very low frequency, the creep effects exist [33,59]. With decreasing frequency, the macroscopic strain (Figure 2a) increased and in the same course the unit cell distortion as well as the tetragonal phase fraction occurred.…”

“…Self-heating generally leads to degradation and affects the lifetime, durability and the positioning accuracy of the actuator and is caused by mechanical and dielectric loss, which can be related to the piezoelectric displacement hysteresis [25,29,30]. Another impact of the frequency is found by previous works investigating both lead-containing and lead-free materials, showing an exponential decrease of the coercive field, with higher frequencies [26,[31][32][33].…”

Spontaneous ferroelectric order in lead-free relaxor Na1/2Bi1/2TiVenkataraman1, Hinterstein2, Lee3 et al. 2020Phys. Rev. B15000View full textAdd to dashboardCite

“…"Strain, Texture, and Rietveld Analysis for Piezoceramics" (STRAP) [50] and the phase fraction extracted from the refined dataset are plotted in Fig. 4.…”

Multi-analyser detector (MAD) for high-resolution and high-energy powder X-ray diffraction

“…In this article, we present a ten-channel MAD for the powder-diffraction side station P02.1 (Dippel et al, 2015;Herklotz et al, 2013) at the PETRA III storage ring of the Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany. This side station operates with an undulator as a radiation source at a fixed energy of 60 keV and is dedicated to high-resolution powder diffraction for material science applications (Liu et al, 2017;Hinterstein et al, 2018), in situ and in operando studies (Schader et al, 2016;Geiger et al, 2017Geiger et al, , 2018Mgbemere et al, 2017;Hinterstein et al, 2019;Riess et al, 2019;Lee, Shi, Kumar, Hoffman, Etter, Checchia, Winter et al, 2020;Choe et al, 2015), and total-scattering experiments (Yavuz et al, 2015). Together with proper synchronization with a periodic excitation, this detector can also be used for high-resolution in situ and in operando stroboscopic measurements on materials under the influence of external stimuli (Liu et al, 2020;Choe et al, 2015).…”