Ndalo < Sub > 3 < / Sub > - Catio < Sub > 3 < / Sub > Microwave Dielectric Ceramic Materials Modification Research

With the rapid development of land mobile communication, the need for microwave ceramics with medium dielectric constant, low loss and low temperature coefficient of resonance frequency is becoming more and more. Of these microwave ceramics, NdAlO3-CaTiO3ceramic has better microwave performance and good stability of temperature, so the study of it has great theoretical and application value.The effect of modification of0.32NdAlO3-0.68CaTiO3formula and technology on phase structure, micro-morphology, sintering characteristics and microwave dielectric properties has been analyzed in detail in the paper. To get the ceramic with good structure and better performance, the influence of non-stoichiometric, substitution and doping is studied. To get an overall preparation technology, milling, sintering and synthetic technology are analyzed.The results of formula modification study are shown as follows:(1) proper adjustment of the non-stoichiometric of Nd ion, Ti ion and Ca ion can improve the sintering characteristics, structure’s densification and micro-properties. When the amount of Nd2O3is0.2wt%, the performance is best:εr=44.92, Q×f=37295(3.282GHZ). When the amount of TiO2is0.2wt%, the performance is best:=44.78,Q×f=36180(3.226GHZ). When the decrease of Ca ion is0.3wt%, the performance is best:εr=44.8, Q×f=36989(3.207GHZ).(2) when the amount of Nd ion replaced by La ion is60%, the structure and the performance are greatly improved, and the performance is εr=45.96、Q×f=39714(3.708GHZ).(3) Doping with1wt%MnCO3can decrease the sintering temperature to1460degree, the performance is εr=42.7、Q×f=36496(3.427GHZ).(4) Doping with0.5wt%CeO2can improve the sintering performance and the micro-properties, the performance is εr=44.75、 Q×f=41493(3.795GHZ)The results of preparation technology study are shown as follows:During the produce of the ceramic, one step synthetic technology can get the best performance; the performance of the ceramic by ball milling is better than by planetary ball milling; by comparing the performance under different presintering conditions, the1270degree is best; when the sintering temperature is1500degree, the longer the holding time the better the performance; the slower the temperature decrease the better the performance.