Papers by Keyword: PLZT

Abstract: Lanthanum-modified lead zirconate-titanate (PLZT5/54/46) powders were prepared from the commercial PbO, La2O3, TiO2 and ZrO2 powders by high-energy ball milling process. The synthesized powders milled for different hours were characterized using XRD and SEM. Thedesigned PLZT perovskite phase was formed from the mixture of the starting materials after milling for 20 hours. PLZT(5/54/46) ceramics were obtained using the produced powders milled for 20 h followed by sintering at temperatures ranging from 1000 to1200°C. Ferroelectric property of the PLZT ceramics was also measured.

Abstract: The Ag-Pd/PLZT composites were prepared by the conventional electronic ceramics method. The electrical and mechanical properties of the composites were investigated. As the amount of doped Ag-Pd particles increased, the fatigue and mechanical properties of the composites were improved, and the dielectric and ferroelectric properties after electric fatigue dropped less. The results indicate that the fatigue process leaves less damage on the composites due to the Ag-Pd particles incorporation. It is proposed that the improvement of fatigue property may be attributed mainly to the improvement of mechanical property.

Abstract: Lead lanthanum zirconate titanate (known as PLZT) ceramic powders have been prepared by the modified sol – gel method, and underwent consolidation by the hot uniaxial pressing method. Application of such technique of preparation permitted to receive fine-grained transparent PLZT x/65/35 ceramics, with x = 8 -10 La at.%. The present publication gives a detailed account of the relationships between technology and physical properties of obtained materials. To analyze all ceramics SEM, EDS and mercury porosimetry were performed, and dielectric properties were studied too. Quite wide light transparency from the visible to nearinfrared range for PLZT ceramics was detected using optical absorption and infrared spectroscopy.

Abstract: Photovoltaic lead lanthanum zirconate titanate films in a layered structure of different crystallographic orientations are fabricated by an optimized metalorganic deposition method. Such films of (001) orientation exhibit a photovoltaic electrical power of approximately 20 times higher than that of random films. The anisotropic optical properties of the oriented films, including dark conductivity, photoconductivity and photovoltaic tensor surfaces, are obtained quantitatively. These results show that the photovoltaic output current and power of the oriented films are highly improved to be equal to those of semiconductors and suitable for application in the optical sensor of micro-electro-mechanical systems.

Abstract: Lanthanum modified lead zirconate titanate (PLZT) thin films were fabricated on indium doped tin oxide (ITO) - coated glass substrate by sol-gel method. The structure of the films was characterized with XRD and SEM. In the case of PLZT the dielectric function was modelled as a sum of Lorentzian oscillators and found by fitting the transmittance and reflectance spectra measured at normal incidence in the wavelength range of 220-2400 nm. The anomalous behaviour of dielectric function was observed below the absorption edge that was suggested to be due to formation of some defect states. The evolution of the absorption edge as well as dielectric function with film thickness was observed and discussed.

Abstract: This paper reports on the formation of film structures and the highly improved photovoltaic output current of the lead lanthanum zirconate titanate (PLZT) employed. The photovoltaic effect of ferroelectrics has the advantage of its simple mechanisms of non-bias applications which are indispensable for semiconductor p-n junctions. But the output current of PLZT bulk is too low for use as a device current source. The PLZT film structure exhibited μA output current upon light illumination. The photovoltaic current of the PLZT film was more than 102 times than that of bulk PLZT. These differences are due to the characteristics of the design of the film including the configuration of the electrode. The PLZT film also has the advantage of easy output control and suitability for use on Si. Results show that the photovoltaic effect of the ferroelectric film is useful as the current source for micro-electro-mechanical systems (MEMS).