| Brief reviews on the theory, background and significance of Piezocearmics are being made at the beginning of this thesis. Based on this, several supplementary guidelines are given out in the composition design.A serial of PZN-PZT based piezoceramic samples with different Zr/Ti ratios are synthesized by adopting the two-step method. The influence that the Zr/Ti ratios have on the ceramic crystal structure and its properties are studied through the research carried out about the relative respects of the fabricated samples. The increase of Zr/Ti ratio can result in the crystal structure transformation from the tetragonal to the rhombohedral, it can also induce the weakness in the stability of the ceramic crystal structure, for example, the drop in the Curie Temperature.In order to enhance the relative low mechanical quality factor of PZN-PZT system piezoceramics, component addition Pb(Mn1/3Sb2/3)O3(hereafter abbreviated as PMS) are introduced in to form a new psudo-tetragonal system ceramics. It has been found that all the elements in the addition act respectively in the way that affect the material's properties during the calcining process and the increase of the PMS/PZN ratio can weaken the stability of the crystal structure of the sintered ceramics and cause the crystal structure transformation from the tetragonal to the rhombohedral as well.Small amount of Nb, Mn dopants could bring high the Qm factor of PMS-PZN-PZT based ceramic, so can it bring down the stability of the material crystal structure. To go a step further, if the Ce dopant is introduced, it may deteriorate properties from all respects except for a higher density.The sample with an optimized composition is fabricated in PMS-PZN-PZT ceramic system, and it shows the best general properties: p 7.84 g/cm3, εr 1295, tanδ =0.0038, d33=304,Kp=0.62, Qm=1220,Tc300℃. |
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