Giant piezoelectric properties of BZT–0.5BCT thin films induced by nanodomain structure

Abstract

Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (BZT–0.5BCT) thin films were prepared from two ceramics targets, Ba(Zr0.2Ti0.8)O3 and (Ba0.7Ca0.3)TiO3, using dual-magnetron sputtering, and a LaNiO3 (LNO) seed layer was introduced between the film and Pt(111)/Ti/SiO2/Si substrates via a sol–gel technique.

Lead‐Free Polycrystalline Ferroelectric Nanowires with Enhanced Curie Temperature

“…In particular, low‐dimensional ferroelectrics have attracted considerable attention, due to confinement‐induced enhancement of polarization and strain‐mediated depolarizing effect in nanodomains that give rise to improved ferroelectric as well as piezoelectric properties . For example, it has been theoretically predicted, and experimentally reported, that strain engineering in ferroelectric epitaxial films on lattice mismatched substrates can facilitate large shifts in the Curie temperature ( T C ) and enhancement in the remanent polarization ( P r ) of these materials. These effects are especially useful in the case of lead‐free ferroelectrics with low T C which often limits their practical use.…”

Thickness effect on the structure, grain size, and local piezoresponse of self-polarized lead lanthanum zirconate titanate thin films

“…The larger correlation length n in the present study and its maximum value observed for the film with 350 nm in thickness are two aspects to punctuate. The correlation lengths obtained in this work are about two to three times larger than those reported in literature for PLZT ceramics at the same composition 31 and comparable to larger values observed for Ba(Zr,Ti)O 3 -(Ba,Ca)TiO 3 (BZT-BCT) thin films, 32 while the typical correlation lengths observed for relaxor thin films are $80 nm. 33 Although it remains unclear the relationship between correlation length and its real value at macroscale, we assume that n is directly related to the average size of polar nanoregions (PNR) in relaxors 34 and thus it can be used to measure the polarization disorder on the surface of the relaxor films.…”

“…These results are consistent with previous report on the grain size effect in PLZT ceramics, which demonstrated larger correlation length for larger grain size. 32 Large correlation lengths obtained in the present work suggests larger PNRs in the studied PLZT films. In literature, large PNRs observed in BZT-BCT films (n $ 151 nm) have been attributed to stronger polar correlations due to the seeded layer grown between the film-substrate such that the seed layer is the responsible for nucleation and growth of large nanodomains.…”

Ferroelectric and piezoelectric properties of Ba0.85Ca0.15Ti0.90Zr0.10O3 films in 200 nm thickness range

“…Although there are some reports on BZT‐BCT thin films up to now, reports revealing the excellent dielectric, ferroelectric and piezoelectric properties of BZT‐BCT films are limited. Li et al reported giant piezoelectric properties ( d 33 = 258 pm/V) of BZT‐0.5BCT thin films synthesized by magnetron sputtering, however ferroelectric properties of the films were not reported. Wang et al reported high remanent polarization ( P r = 22.15 μC/cm 2 ) for sol‐gel developed thicker (800 nm) BZT‐0.5BCT film without any report on the piezoelectric properties.…”

“…The piezoelectric films were developed by simple sol‐gel methodology without any seed layer. From the literature it is observed that except Li et al, almost all the communications made so far on BCZT thin films having thickness range ≥400 nm. The present report reveals that a 200 nm BCZT film developed by sol‐gel technique is able to show excellent ferroelectric properties.…”