The preparation and properties of Pb/sub 5-x/Ba/sub x/Ge/sub 3/O/sub 11/ ceramics for pyroelectric applications

Dense polycrystalline ceramic bodies of the barium derivative, Pb/sub 5-x/Ba/sub x/Ge/sub 3/O/sub 11/, were prepared via the sintering of recrystallized glass powders. Barium doping levels varied from x=0.1 to x=0.5. Phase development in the system was studied by thermal analysis and X-ray diffraction and microstructural development by scanning electron microscopy. When the concentration of Ba was low (x<0.3) there was a complete solid solution with lead germanate. At higher barium concentration, there was a formation of BaPb/sub 8/(Ge/sub 2/O/sub 7/)/sub 3/. The sintering behavior at different temperatures was studied by dilatometry. Ceramics sintered at 710 degrees C were of 95% theoretical density. The results are discussed in terms of the effect of microstructure upon the dielectric properties.<
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