Search results for "ferroelectric"

The Effect of Technological Factors on the Synthesis of PbMg 1/3 Nb 2/3 O 3

2003

Conventional technique of solid phase reactions allows one to obtain PbMg 1/3 Nb 2/3 O 3 material with about 20 vol.% of the pyrochlore phase. The latter can be reduced to 5 vol.% by Swartz-Shrout two-stage solid state reaction via MgNb 2 O 6 having the columbite structure. A single-phase perovskite product can be obtained by by the two-stage columbite method from mixtures containing 0.2 mol. parts of overstoichiometric MgO. The best results are obtained by using magnesium carbonate hydroxide pentahydrate (MgCO 3 ) 4 ·Mg(OH) 2 ·5H 2 O as the magnesium source. The modified route yields stoichiometric single-phase PMN.

Production and Properties of Lead Scandoniobate Ferroelectric Ceramics Doped with Rare-Earth Oxides

2001

Modified PbSc<sub>1/2</sub>Nb<sub>1/2</sub>O<sub>3</sub> Ferroelectric Ceramics

1997

Corrigendum to “Far-infrared and THz spectroscopy of 0.4PMN–0.3PSN–0.3PZN relaxor ferroelectric ceramics” [J. Eur. Ceram. Soc. 27 (2007) 3713–3717]

2007

FERROELECTRIC LIQUID CRYSTAL GLASSES FOR AMBLYOPIA RESEARCH

2008

ABSTRACT Ferroelectric Liquid Crystal (FLC) filters offer the speed of electronic light shutters and the vibration free operation. These characteristics make them ideal for applications requiring short exposure times and minimal blur, offering switching times of 0.0002 of a second. FLC filters can be used as the optical shutters for machine vision purposes, also in vision research. On the basis of FLC filters we have developed ferroelectric glasses, allowing temporal separation of optical information for both eyes. In the case of amblyopia (“lazy eye”) the only way to oblige the “lazy” eye to work is to close the other better-seeing eye. We advice an appliance for dynamic visual system trai…

Dielectric nonlinearity of ferroelectric solid solutions PMN-PZN and PMN-PNN

2001

Abstract Obtaining of novel thin film materials for electrically tuneable capacities is one of the current problems of ferroelectric material application. The most appropriate materials are the ferroelectric lead-containing niobates: PbMg1/3Nb2/3O3 (PMN), PhZn1/3Nb2/3Os (PZN), PbNi1/3Nb2/3O3 (PNN) and their solid solutions were synthesized by solid state reactions at 800–900 °C from oxides. Results of the studies of thermal dependence of dielectric permeability and loss factors of the synthesized solutions are provided together with reciprocal dielectric permeability as function of temperature and electric field intensity. The dielectric characteristics of nonlinear materials are reported e…

Influence of Compressive Stress on Dielectric and Ferroelectric Properties of the(Na0.5Bi0.5)0.7Sr0.3TiO3Ceramics

2013

Good quality lead-free ceramics of (Na0.5Bi0.5)0.7Sr0.3TiO3(NBTS30) have been produced by a solid phase sintering process. The dependence of dielectric and ferroelectric properties on the unaxial pressure (0–1200 bar) were investigated. A shift and decrease of maximum value of e, decrease of the thermal hysteresis and coercive field and increase of polarization with increasing pressure were observed. The results were discussed in terms of an elastic changes in inter-ionic distances in a crystal structure and switching nanoregions under the action of pressure. The NBTS30 ceramic is expected to be a new promising candidate for lead-free electronic material.

A New Opto-dielectric Effect Based on the Photoisomerization of Azo Compounds in Ferroelectric Liquid Crystals

1995

A multiaxial electrical switching in a one-dimensional organic–inorganic (pyrrolidinium)2Cd2I6ferroelectric and photoluminescent crystal

2021

Ferroelectric materials exhibiting more than one polar phase are very attractive in terms of application. The advantage of such materials is temperature-dependent switching between two different ferroelectric states. Here we report on the discovery of a unique, continuous ferroelectric – ferroelectric transformation in (C4H10N)2[Cd2I6], PCdI at 220 K. Thermal measurements suggest that phase transition is close to the continuous one. Both phases belong to the same polar monoclinic Cc space group. Temperature-variable X-ray diffraction measurements of single crystals confirm the polar nature of the two phases (I and II). The anionic network is in the form of [Cd2I6]2− 1D chains, with pyrrolid…

Conductance control at the LaAlO3/SrTiO3-interface by a multiferroic BiFeO3 ad-layer

2014

Multilayered BiFeO3 (BFO)/LaAlO3 (LAO) thin film samples were fabricated on SrTiO3 (STO) substrates by pulsed laser deposition. In this work, the ferroelectric polarization of a multiferroic BFO ad-layer on top of the quasi-two-dimensional electron gas (2DEG) at the LAO/STO interface is used to manipulate the conductivity of the quasi-2DEG. By microstructuring the conductive area of the LAO/STO-interface, a four-point geometry for the measurement of the resistivity was achieved. Piezo force microscopy allows for imaging and poling the spontaneous ferroelectric polarization of the multiferroic layer. The resistance changes showed a linear dependence on the area scanned and a hysteretic behav…