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Conventional piezoelectric materials based on PZT have a transition temperature of around 350degC, providing reliable operation up to only 250degC. However, there is considerable need for high temperature actuation and sensing, for example the aerospace industry has a requirement for technologies that will perform in extreme environments. We report on an exciting group of high temperature piezoelectric...
In this work, the effect of two stage sintering and sintering temperature on dielectric properties of perovskite PbTiO3 ceramics are reported. High density lead titanate (PbTiO3) ceramics were prepared by a solid solution method. Several sintering temperatures were selected to prepare the samples. The dielectric constant of these samples was measured in a frequency range from 100 Hz to 1 MHz. Thermal...
Recording density, domain switching time and bit error rate were evaluated using a data storage system based on scanning nonlinear dielectric microscopy. Congruent lithium tantalate single crystals with the thickness less than 50 nm were used as recording media. Local domain switching was carried out by applying voltage pulse on the recording media using a conductive cantilever. Close-packed domain...
Crack free peroviskite 0.2PZN-0.8PZT (53/47)) thick films up to 6.8 ??m were prepared by a metallic-organic decomposition (MOD) process on platinum coated titanium (Pt/Ti) foil substrates by a dipping coating technique. The thick film exhibits a pure perovskite phase structure with dense and uniform microstructure. The dielectric, ferroelectric and piezoelectric properties of the thick film have been...
A single PZT metallic target has been utilized to deposit lead zirconate titanate (PZT) films by DC pulsed magnetron sputtering on Ti/Pt(111)/Ti coated Si wafer and on Au coated glass fibers. Multicrystalline PZT films were obtained after post treatment by conventional (CA) and rapid thermal annealing (RTA) at 650??C in air and vacuum. The influences of both post-annealing treatments on the film properties...
We report here, the study of domain inversion in lithium niobate (z-cut) by electron beam irradiation without any static bias associated to wet etching, in view of the fabrication of phononic crystals. The inverted domains are revealed by HF-etching taking advantage of the large difference in etching rate between z+ and z-faces. A pertinent choice of irradiation conditions such as accelerating voltage,...
Heterostructures of thin-film perovskite ferroelectrics and relaxors were grown by in situ pulsed laser deposition on La0.5Sr0.5CoO3/MgO and Pt/sapphire. The dielectric response of the heterostructures was measured as a function of frequency, temperature, amplitude of ac field, magnitude of dc field, and varying the measurement rate. In the ferroelectric state, the existence of ferroelectric domains...
A transducer for a micro ultrasonic scalpel has been fabricated. The micro ultrasonic scalpel can be used with an endoscope for a non-abdominal operation or micro surgery, for example, through a microscope. The ultrasonic transducer was 9.8 mm long and 2.7 mm wide and has stepped horn to amplify vibration velocity; tip of the horn is 0.6 mm wide. The scalpel vibrated in longitudinal mode at about...
Ambient energy scanvengers have the potentials to replace batteries, which have limited lifetime and large volume, and to realize the miniaturized devices. Piezoelectric materials have been testified as a promising candidate for converting vibration energy into electric energy. The conversion efficiency depends on the types of piezoelectric materials and structural designs. PZT, PVDF and MFC cantilevers...
A new piezoelectric Coriolis vibrating gyro (CVG) is presented in this article. There is a real need for integrated inertial sensors (e.g. for vehicle attitude control or inertial navigation) and ONERA (the French National Establishment for Aerospace Research) has been developing a quartz micromachined CVG called VIG (vibrating inertial gyro). Quartz was chosen in regard to its mechanical quality...
In this study, in order to develop the composition ceramics for low loss and low temperature sintering multilayer piezoelectric actuator, PMN-PNN-PZT ceramics were fabricated using Li2CO3 and Na2CO3 as sintering aids, and their piezoelectric and dielectric characteristics were investigated according to the amount of MnO2 addition. At the sintering temperature of 900 , density and mechanical quality...
By analyzing Landau's phenomenological thermodynamic potential, we propose a few ways to assess the importance of eighth-power terms and to verify the temperature dependence of the anharmonic coefficients. It is demonstrated that the eighth-power terms should be substantially involved for the adequate description of the thermodynamic behavior of BaTiO3 around the cubic-tetragonal phase transition...
This paper developed a single right angle line-focusing ultrasonic transducer array to detect all the dents, metal loss and crack-like flaws. By using the A-scan ultrasonic signals captured from the array, 2D images of the pipe flaws can be obtained, so the size and location of the flaw can clearly be got. In this paper, the algorithm for flaw 2D-reconstruction is presented. Meanwhile, a wavelet-based...
This work proposes a method of efficiently modeling the hysteresis of ferroelectric materials, such that the finite element analysis of complex structures will be possible. Our approach includes the additive combination of a reversible and an irreversible portion of the polarization and strain, respectively. Whereas the reversible parts correspond to the common piezoelectric linear equations, the...
The electric properties of bismuth- and sodium-modified barium titanate, Ba1-x(Bi1/2Na1/2)x TiO3 (BBNT) were studied as a lead-free PTC (positive temperature coefficient of resistivity) thermistor material usable over 130??C. Two semiconductorization processes and their electric properties are described. Lanthanum(La)-doped BBNT ceramics sintered in air still show dielectric behaviors, but Nb-doped...
Investigations in the development of lead-free piezoelectric ceramics have recently claimed properties comparable to that of PZT-based materials. In this work, the dielectric and piezoelectric properties of the various systems were contrasted in relation to their respective Curie temperatures. Though comparable with respect to TC, enhanced properties reported in the K,NaNbO3 family are the result...
Bismuth ferrite lead titanate (BFPT) films of composition xBiFeO3 - (1-x)PbTiO3, with x from 0 to 1, have been deposited on platinised silicon substrates employing pulsed laser deposition under various temperatures and oxygen pressures. Dense, high quality films were deposited at 530??C with 150 mTorr oxygen pressure. The crystal structure and orientation of the films has been studied by powder x-ray...
After an evaluation of Zr precursor, quatemary Pb(Zr,Ti)Ox [PZT] films were prepared by a combination of binary atomic layer deposition (ALD) processes. ZrOx films were deposited on Pt/TiOx/SiOx/Si substrates using liquid injection ALD. Zr(C11H19O2)4 [Zr(DPM)4] dissolved in ethylcyclohexane (ECH) with a concentration of 0.1 M and water were used as precursor and oxidant, respectively. According to...
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