The preparation and properties of Pb5-xBaxGe 3O11 ceramics for pyroelectric applications

Dense polycrystalline ceramic bodies of the barium derivative, Pb _5-xBa_xGe₃O₁₁, 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 BaPb₈(Ge₂O₇) ₃. The sintering behavior at different temperatures was studied by dilatometry. Ceramics sintered at 710°C were of 95% theoretical density. The results are discussed in terms of the effect of microstructure upon the dielectric properties