| Lead Zirconate Titanate (PZT) is the ceramic material which has a typical perovskite structure and a variety of advantage properties including ferroelectricity, piezoelectricity, dielectric and pyroelectric which make it has been widely applied in microelectronics, optoelectronics, integrated optics, micro electro mechanical systems, etc.In this work, analytical pure PbO, ZrO2and TiO2were used as raw materials. PZT targets with different components were fabricated by conventional solid-state sintered method. It has been found that the powders were first presintered powders at850for2hours, and then the targets were sintered at1050for8hours was the optimal processing condition. X-ray diffraction patterns showed that the PZT ceramics were of pure perovskite structure. The diffraction peak shifted to left when the Zr content was increased, meanwhile, the intensity of the peak increased gradually and the lattice constants also changed. When the ratio of Zr to Ti was52/48, the dielectric constant of PZT ceramic reached to the biggest value of534, correspondingly, the dielectric loss value was0.04, which were in agreement with the required value for the fabrication of piezoelectric devices.Three series of rare earth doped PZT, PEZT(Pb1-xEux(Zr0.52Ti0.48)1-x/4O3) PDZT(Pb1-xDyx(Zr0.52Ti0.48)1-x/4O3) and PLZT(Pb1-xLax(Zr0.52Ti0.48)1-x/4O3) targets were prepared by solid stated sintered method.It was found that all ceramics have pure pervoskite structure preferable densities and dielectric properties.For series A(PEZT), the optimal condition for preparation was that presinteried at850for2h, then sintered at1050for12h. The value of dielectric constant increased with Eu content increasing. The biggest value390was obtained at2at%of Eu doping and the dielectric loss was0.0097at this condition. At the same time, the piezoelectric constant also reached to the biggest value of256pC/N. But the dielectric constant decreased and dielectric loss increased while the Eu content was more than2at%. It indicated that the appropriate content of Eu doping could improve the dielectric properties of PZT ceramic.For series B(PDZT), the optimal preparation condition was that presinteried at900for2h, then sintered at1000for12h. The biggest dielectric constant value382, the optimal piezoelectric constant298pC/N, and the small dielectric loss0.016were obtained at lat%of Dy doping.For series C(PLZT), the optimal preparation condition was that presinteried at950for2h, then sintered at1075for12h. The dielectric constants of La doping targets were all improved compared to the undoped targets. When La doping content was1at%, the biggest dielectric constant value498, the optimal piezoelectric constant325pC/N, and the small dielectric loss0.011were obtained.PZT films with different component and different rare earth doping were prepared on SrTiO3(001) substrates by pulsed laser deposition (PLD) technique.The crystalline and structural characteristics of PZT films with different Zr to Ti ratio x (x=0.8,0.7,0.48,0.3,0.2) and different rare earth element doping (Eu, Dy, La) were studied by X-ray diffraction machine. The results showed that all the films were of pure phase and grown along c axis. And the change of Zr to Ti ratio, doping element and the doping content can influence the crystalline quality of films.The surface morphology of films were studied by atomic force microscopy (AFM). Small root mean square roughness were obtained, indicating that the films prepared have smooth surfaces. On the same condition of deposition, the optimal films with high quality surface were Eu doping content of2at%, Dy doping content of2at%and La doping content of3at%respectively.As shown in the rocking curves, the full width at half maximum (FWHM) of the diffraction peak of the PDZT films changed slightly with Dy content increasing. For PLZT films, the FWHM of peak were relatively small. When the doping content of La was2.5at%and3at%, the FWHM were0.27and0.35, respectively, indicating the high quality crystalline of films were obtained. Finally, the grain size were calculated and the dopant distributuion of the doping ions into the PZT lattices were analysised... |
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