Research On The Hot-press Sintering Process Of Nb, Mn, Sb Doped Lead Zirconate Titanate Ceramics

High performance and inexpensive pyroelectric infrared sensors play an important role in the field of thermal detection and imaging of objects. So, the properties of pyroeletric materials have attracted many researchers. As the grain size of hot-pressed materials is small and uniform, the grain boundary is tight and seldom congeals impurities, so this kind of materials are transparent with high rigidity. So, hot-pressed PMNSZT materials are studied in this article.The influences of Oxygen atmosphere to the properties and the micro structure of the material have been studied, the effect of oxygen atmosphere in eliminating the oxygen vacancies is discussed. The sintering temperature with oxygen and hot-press pressure to the properties and the microstructure of the materials have been discussed, the effect of hot-press pressure in compacting the material is analyzed.The main conclusions are as follow:It could be inferred from the SEM picture that the grain size uniformity of oxygen-sintering material is better than that of the traditional sintered bodies. And the grain growth of oxygen-sintered material is favorable, the grain boundary is clear with the grains compacted together. The conclusion could be drawn that oxygen-sintering could reduce the sintering temperature of the material, so as that the grain size of oxygen-sintered material is larger than that of the traditional sintered samples at the same temperature.Green bodies are oxygen-sintered at different temperature. Through comparison, the ceramic body sintered at 1210℃has higher pyroelectric coefficient as much as 20×10-8C/cm2K from 33 to 36℃, the relavant FD reaches as high as 22×10-5Pa-0.5. Analytically, the high pyroelectric current may be caused by FRL-FRH phase transition.Green bodies are oxygen-sintered at different pressure at 1210℃, through SEM pictures, the conclusion could be drawn that, with the increasement of hot pressure, the size of the grain is increasing too, and the shape of the grain is changing from round to polygon. This may be explained as follow: grains are squeezed together under high pressure, so the grain boundary is squeezed to polygon, this would make the gas hole eliminating from the body more easily. What's more, the density and the pyroelectric coefficient are increasing with the increasement of hot pressure.