Papers by Keyword: Lead Magnesium Niobate

Abstract: Perovskite relaxor ferroelectric PMN ceramics, Pb (Mg_1/3Nb_2/3O₃), have been fabricated using a two-stage process employing a corundum-type Mg₄Nb₂O₉ as a key precursor. The 100% perovskite PMN ceramics was revealed by X-ray diffraction analysis. The SEM image of the PMN ceramic shows irregular shape PMN grains on the porous surface. The surface chemical composition of the PMN ceramics could be characterized by X-ray photoelectron microscopy technique. The XPS results indicate most of the elements consist of more than one chemical species. The important of XPS studies here can reveal small amount of species which could not detected by XRD.

Abstract: PZT-PMN ceramic system with presence of MnO2 contents were proposed and prepared using conventional sintering method as for piezoelectric transformer application. Phase formation and several dielectric and piezoelectric parameters were studied as a function of MnO2 concentration. The x-ray diffraction study revealed the tetragonal symmetry for all samples with MnO2 doping. To determine polarization, the P-E hysteresis loop were produced and the results indicated that entering of Mn4+ ions in the ceramic structure created large amount of oxygen vacancies and the consequent was observed as displacement of the loops to E axis. The obtained optimum parameter are d33 = 119 pC/N, kp = 0.207, Qm = 1669, tan = 0.0101, Pr = 20 μm/cm2 and Ec = 10 kV/cm.