PbOを含む高誘電率磁器, 特に高温度におけるPbOの蒸発について

抄録

High permittivity ceramics containing PbO have many useful characteristics for electrical application, for example, PbTiO₃-PbZrO₃ for electro-acoustic transducer, BaTiO₃-PbSnO₃ for non linear element of electric circuit and so on. But as the firing of these ceramics is generally accompanied by the evaporation of PbO, it was difficult to get a dense ceramic body, the fact which has prevented the practical application of these materials.
The author has investigated systematically the evaporation of PbO from the ceramics having various compositions as the functions of both temperature and time using the thermobalance with strain meter. It was confirmed that the rate of the evaporation of PbO from the specimen was affected by the factors such as the composition and moulding pressure, etc.
Resting on the results of the investigation the author has set up an industrial method which gives a dense body containing PbO without using such precious metal as platinum. The electrical characteristics of the products were measured with the results which proved that they have excellent, uniform and reproducible properties.