Papers by Keyword: PZT

Abstract: The aim of this paper is to understand the effects of the damage criteria modelling on the training phase (performed by means of Finite Element simulations) of an artificial neural network (ANN) enabled to locate impacts onto a CFRP laminate. The developed FE models have been also used to investigate the intra-laminar damage mode, which, among different ones, has the most effects on the residual strength of the panel.

Abstract: Some piezoelectric properties of lead zirconate titanate PbZr_0.53Ti_0.47O₃ ceramic samples sintered at 1100oC for 3 hours has been investigated in this work and compared to the strontium modification at 0.2, 0.4, and 0.6 mol%. Polarization versus Electric Field curve and d₃₃ and K_p piezoelectric parameters was taken at room temperature in order to investigate the correlation with phase amount and lattice parameters of crystalline phases calculated through Rietveld refinement. The results indicated the lead substitution with 0.4 mol% of strontium enhances the d₃₃ and K_p piezoelectric parameters, but there is no systematic variation of the piezoelectric properties with strontium content. By the other hand, tetragonal phase seems plays an important rule on piezoelectric devices operating near the room temperature and some correlations could be found.

Abstract: Strontium-modified lead zirconate titanate ceramics was prepared by the polymeric precursor method. The effect of Pb (II) substitution by Sr (II) in A site of the perovskite structure at molar percentages of 0.0, 0.2, 0.4 and 0.6 mol% was investigated through XRD and Rietveld method. The increasing of strontium amount displaces the morphotropic phase boundary toward to tetragonal phase and that results can be associated to the tetragonal lattice expansion besides the rhombohedral opposite phenomenon. The effect of strontium substitution on the dielectric properties for sintered ceramics is also investigated and showed the strontium substitution leads to reduction of weight loss and increasing of density for sintered ceramic. The Kc and Tc oscillates as function of ceramic morphology and is not possible to verify the existence of conductive intergrains defects by loss tangent curves. An intrinsic event can be occurring because considerable lattice distortion was verified in tetragonal and rhombohedral structures for powder samples.

Abstract: In this paper, the dielectric and electrowetting properties of Pb (Zr_0.4Ti_0.6)O₃ (PZT) ferroelectric thin film are studied as the dielectric layer in electrowetting-on-dielectric (EWOD) device. The PZT thin film is formed by spin-coating, pyrolysis and annealing. The characterization results show that PZT thin film can serve as the dielectric of EWOD with a high dielectric constant and a great electrowetting performance when used in silicon oil bath environment. To test the electrowetting effect, a EWOD device with 200nm thick PZT ferroelectric thin film dielectric layer is fabricated. The variation of contact angle between droplet and device surface achieved with DC voltage, AC voltage and AC frequency change of electrowetting on PZT are fully experimented. The EWOD device with PZT dielectric layer can manipulate water droplet at low driving voltages. This study shows the potential of using ferroelectric ceramic material as the dielectric layer in high-performance EWOD devices.

Abstract: The ferroelectric ceramics with composition of (1-x)Pb(Zr_0.52Ti_0.48O₃ [PZT] – x(Ba_0.9Ca_0.1)(Ti_0.85Zr_0.15)O₃ [BCZT] (x = 0, 0.04, 0.08 and 0.10 ) have been successfully prepared via two-step mixed oxide method. The material systems of lead zirconate titanate (PZT) and barium calcium zirconate titanate (BCZT) have been intensive studied due to their remarkable properties of high ferroelectric and piezoelectric values. In this work, we are interesting to combine PZT with BCZT system in order to improve the electrical property of the ceramic samples. From the obtained results, it can be confirmed that ferroelectric values are significant increased with the optimum amount of the BCZT.

Abstract: PZT ceramic is synthesis by using sol gel method.Introducing a dopant to the pure PZT can help to enhance the properties of the piezoelectric ceramic. The effects of sintering temperature on phase formation, densification of the ceramics have been investigated using XRD, SEM and Archimedes method. The bulk density and porosity of PZT decreased as the sintering temperature increased.

Abstract: The results of the experimental study of the critical X-ray scattering (CS) in PbZr_0.6Ti_0.4O₃ (PZT40) single-crystal are presented. Temperature evolution of the CS lineshape and intensity was analyzed. It is demonstrated that CS can be described in terms of the mean-field model. Temperature dependences of the peak intensity of the CS, proportional to the static susceptibility, and the correlation length of the «ferroelectric fluctuations» follow the Curie-Weiss law with the Curie temperature T_c=638 K. Obtained results confirm the second-order character of the phase transition in the PZT40.

Abstract: Bilayer thick films of sacrificial titanium dioxide and Nb-doped lead zirconate titanate (PZTN) have been deposited on bare silicon wafers using electrophoretic deposition (EPD) technique. Deposition of such ceramic particles, dispersed ethanol-based suspensions, on semiconductor substrate has been made possible after preparation of alloyed junctions Al/Si characterized by ohmic behaviour. Sintering of green TiO₂/PZTN films was performed at 900 °C for 1 h. The composition of the films, the thickness and relative density of the deposited materials have been analysed by EDS-SEM analysis. The lead diffusion through the silicon wafer has been reduced.

Abstract: Large area film deposition was performed by means of multitarget reactive magnetron sputtering from metallic targets (Pb, Ti, Zr) with a diameter of 200 mm onto Cu-coated Kapton® HN substrates. High-power pulse sputtering has been employed for the Zr-target (or alternatively for the Ti-target). Film composition profiles were evaluated by XPS and RBS. Piezoelectric properties were investigated by PFM.

Abstract: The effects of the complex donor and acceptor additives on the microstructure, piezoelectric and dielectric properties of PZT (Zr/Ti=53/47) ceramics were studied. A complex doping with the soft (La⁺³ and Nb⁺⁵) and hard (Fe⁺³ and/or Mn^{(+2,+3 or +4)}) ions has been adopted. The complex doping of two or more elements is expected to combine the properties of donor and/or acceptor doped PZT, which could exhibit better stability or improved piezoelectric properties than those of the single element doped PZT. The complex doping caused various compensation effects for the piezoelectric properties of PZT ceramics; Mn addition to the La/Nb and Fe doped PZT composition led to the improved piezoelectric properties, i.e., enhanced Q_m with remaining considerably high k_P.