Abstract
It is well known that the properties of ceramic capacitors are greatly affected by particle size, composition, forming pressure, impurity and firing temperature.
Though there have been many reports made concerning these factors, but little is not known of the method to recover the BaTiO3 once vitrified, and of the effect of using such materials on the propertis of BaTiO3.
This experiment was carried out to reveal the effect of such materials on the properties of the capacitor.
In this experiment, the crushed and classified powder of BaTiO3 once vitrified were used as raw materials.
The classified powder (100-150 mesh, 150-200 mesh, 200-270 mesh, 270-400 mesh, ) pressed 17.5mmφ. 1.2mm thick were fired at various temperatures. The dielectric constant, the dielectric loss, the change of lattice constant, the water absorption, the shrinkage and the curie point were respectively measured.
The results obtaind are summarized as follows:
1. The dielectric constant, the dielectric loss and the shrinkage increased with increased temperature.
2. The water absorption dccreased with increased temperature.
3. The curie point was lowerd with increased temperature.
4. The lattice was expanded with increased temperature.
5. The effect on the bubbles of the classified particles growing large was equal to the rise of the firing temperature.
6. The porosity of the specimens calculated from the dimension and that calculated from the dielectric constant did not agree with each other.
