Sandrine Traversa Gentil

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Transparent single crystals of the perovskite Pb(Zn-1/3,Nb-2/3)O-3-PbTiO3 (PZN-PT) were grown from different lead fluxes in sealed platinum crucibles. A temperature gradient furnace was used (temperature gradient on crucible: 30-50 degreesC). Optimization of growth temperature range and cooling rates was carried out in fluxes of PbO, Pb3O4 with and without an addition of B2O3. The growth nature range was typically 1150 degreesC --> 930 degreesC (on crucible top) with cooling rates of 0.8 - 1 degreesC/h for

The lead magnesium niobate [Pb(Mg1/3Nb2/3)O-3 or PMN], and its solid solutions with lead titanate (PbTiO3 or PT), are of great interest because of their high electromechanical properties. At large PMN content, these materials exhibit relaxor characteristics with large electrostrictive strains and a large permittivity, while compositions near the morphotropic phase boundary present very interesting piezoelectric properties. So far, properties of these materials in ceramic, thin film and single-crystal form h

This paper describes fabrication and characterization results of piezoelectric micromachined ultrasonic transducers (pMUTs) based on 2-mu m-thick Pb(Zr0.53Ti0.47O3) (PZT) thin films. The applied structures are circular plates held at four bridges, thus par ...

Transparent single crystals of Pb(Zn-1/3, Nb-2/3)O-3-PbTiO3 (PZN-PT) perovskite have been grown by the slow cooling method in a temperature gradient furnace. The optimization of growth techniques to crystallize PZN-PT with a cubic habitus is described in details. The growth temperature range and cooling rates was carried out in different lead fluxes, Crystal recovery from the residual flux was obtained by different techniques based on liquid flux elimination at the end of the growth process. The best transp

Ferroelectric capacitive devices for memory and MEMS applications require patterned ferroelectric thin films with high anisotropic etched features. In this paper, physical and chemical parameters during etching of Pb(Zr0.53Ti0.47)O-3 (PZT) by a dual frequency ECR/RF reactor have been investigated. The removal characteristics of blanket films and films with a patterned mask were investigated as a function of gas chemistry (Ar, halogen gases), substrate bias RF power and working pressure (from 5 x 10(-4) Pa t

PZT (PbZrx Ti1-xO3) thin films have been locally grown by means of sol-gel deposition and local annealing on microhotplates. The microhotplates were based on a stress compensated Si3N4 /SiO2 membranes as structural elements and contained tantalum silicide filaments (Ta5Si3) for resistive heating. Above the filaments, a passivation layer of SiO2, an adhesion layer of Ti/TiO2 and a bottom electrode of Pt were deposited. Due to the low heat conductivity of the membrane, crystallization of the PZT film occurs e

In this communication we address two issues essential for low-voltage memory applications of ferroelectric thin films: the size effect on polarization switching, and polarization fatigue. According to the proposed concept, both of these phenomena are controlled by local injection of charge into the interfacial layers of the ferroelectric film. In the experimental part of this work, we show that the entrapped charge relaxation can be enhanced by introducing a thin RuO2 layer into the top interface of the Pt/

Pb(Zr-x, Ti1-x)O-3 (PZT) piezoelectric thin films are of major interest in MEMS technology for their ability to provide electro-mechanical coupling. In this work, the effective transverse piezoelectric coefficient e(31,f) of sol-gel processed films was investigated as a function of composition, film texture and film thickness. Dense, textured and crack-free PZT films have been obtained on silicon substrates up to a thickness of 4 mum. Crystallization anneals have been performed for every 0.25 mum. Nucleatio

The paper describes processing and dielectric properties of 0.65Pb(Mn1/3Nb2/3)O-3-0.35PbTiO(3) films deposited on alumina and silicon substrates by screen-printing. Ink development and problems associated with adhesion of electrodes to substrate are discus ...

By means of transmission electron microscopy (TEM) the structure of chemically ordered regions in Zr-doped Pb(Mg1/3Ta2/3)O-3 has been studied. Large coherent ordered domains were obtained by the addition of 5 mol% PbZrO3. The results obtained by conventional, analytical, and high-resolution TEM are consistent with the random-site description of the B-site order, the so-called random-layer model. Image simulations showed that a careful selection of the imaging conditions for high resolution transmission elec

A shear mode resonator based on bulk waves trapped in c-axis oriented AlN thin films was fabricated, simulated, and tested. The active 1.55 mu m thick AlN layer was deposited on top of an acoustic Bragg reflector composed of SiO2/AlN lambda/4 layer pairs. ...

Sandrine Traversa Gentil

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Flux growth and characterization of quasi cubic PZN-PT single crystals

Pb(Mg1/3Nb2/3)O-3 and (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) relaxor ferroelectric thick films: Processing and electrical characterization

Piezoelectric micromachined ultrasonic transducers based on PZT thin films

Growth and properties of transparent Pb(Zn-1/3, Nb-2/3)O-3-PbTiO3 single crystals with a cubic habitus

Mechanisms of Pb(Zr0.53Ti0.47)O-3 thin film etching with ECR/RF reactor

Local growth of sol-gel films by means of microhotplates

Downscaling of Pb(Zr,Ti)O-3 film thickness for low-voltage ferroelectric capacitors: Effect of charge relaxation at the interfaces

{100}-textured, piezoelectric Pb(Zr-x Ti1-x)O-3 thin films for MEMS: integration, deposition and properties

Development of relaxor ferroelectric materials for screen-printing on alumina and silicon substrates

Direct observation of the B-site cationic order in the ferroelectric relaxor Pb(Mg1/3Ta2/3)O-3

Shear mode bulk acoustic wave resonator based on c-axis oriented AIN thin film