FAST FIRING OF LEAD MAGNESIUM NIOBATE AT LOW-TEMPERATURE

A fast-firing technique for the sintering of lead magnesium niobate re laxer ceramics at relatively low temperature has been described, In th is process, the samples containing excess PbO (up to 5 wt. %) are dire ctly introduced into a furnace maintained at a temperature of 950 degr ees C and kept there for 15-80 min, followed by a postsintering anneal ing treatment at 800 degrees C for 10 h. The importance of fast heatin g as well as annealing treatment has been justified. The sintered samp les are near-phase-pure perovskite materials showing high bulk densiti es (>94%), uniform and dense microstructure, and satisfactory dielectr ic properties (K-max > 13,000). The technique is simple and economic, does not require any controlled atmosphere, and minimizes hazards from lead volatilization.