Coupling of the remanent polarisation in thin film oxide ferroelectrics with nematic liquid crystals

Abstract

The technique of domain visualisation, revealed by a film of nematic liquid crystal (NLC ) on a ferroelectric crystal substrate, is demonstrated for the first time to be applicable to thin films of lead zirconate-lead titanate (PZT ) ferroelectric ceramics. PZT film thicknesses <1 mm were deposited on indium tin oxide coated glass substrates. Commercially available NLC materials with positive dielectric anisotropy were employed. The electro-optic properties of devices incorporating the ferroelectric ceramic and NLC are reported. The poled PZT grains induce a local Fre ´edericksz transition in the NLC and it is proposed that the ferroelectric-NLC interaction is primarily due to the depolarisation field due to the ferroelectric remanent polarisation.

Static and dynamic electro-optical properties of liquid crystals mediated by ferroelectric polymer films

“…20 The consideration of the direct inuence of the spontaneous polarization of ferroelectric substrate on the electro-optics of liquid crystals is an important aspect of paper. 20 Interactions of liquid crystals with the spontaneous polarization of the ferroelectric lm are further explored in papers [21][22][23][24][25] reporting local Freedericksz transitions 21,22,24 and their possible use in electro-optical and memory devices. 23,24 Local reorientation of liquid crystals governed by the spontaneous polarization of the substrate was observed utilizing inorganic metal oxide ferroelectric crystals such as lead zirconate titanate (PZT), [21][22][23][24] and barium titanate.…”

“… 20 Interactions of liquid crystals with the spontaneous polarization of the ferroelectric film are further explored in papers 21–25 reporting local Freedericksz transitions 21,22,24 and their possible use in electro-optical and memory devices. 23,24 Local reorientation of liquid crystals governed by the spontaneous polarization of the substrate was observed utilizing inorganic metal oxide ferroelectric crystals such as lead zirconate titanate (PZT), 21–24 and barium titanate. 25 Recently, PZT-based ceramic in combination with liquid crystals found their application in the design of tunable micro-lens.…”

Domain manipulation of ferroelectric BaTiO3 thin films: application to the local reorientation of liquid crystal

“…A drawback of such an alignment method is the impossibility of controlling the shape of the ferroelectrics domains in such materials. Recently, the alignment of a liquid crystal induced by a large and macroscopically poled area (over 100 mm 2 ) of polycrystalline PZT thin films has been demonstrated [7][8][9]. The manipulation at a sub-micrometer scale of domains of ferroelectric thin films has been demonstrated [10][11][12][13][14] using scanning probe microscopy.…”

Tailored liquid‐crystal switching on ferroelectric polymer films

“…This technique called the domain visualization technique has been used to study the domains in ferroelectric crystalline materials including triglycine sulfate and lead-zirconate titanate. 17 The foundations of this work have been laid out in previous reports of LC alignment on rubbed films of PVDF-TrFE (70/30) formed using a dipping method 13 or spin-coating. 18 However, the switching responses and LC alignment observed in our devices are significantly different from the ones reported.…”