Abstract
The boundary layer capacitor consists of grains as semiconductor and boundary layer as dielectric, and the apparent permittivity of boundary layer capacitor is proportional to grain size. It was studied how to control grain size and apparent permittivity of boundary layer capacitor with seed grains.
The seed grains were produced by grinding the sintered body with same composition of main material. The average particle size of seed grains was about 6 times as large as that of main material.
The grain size(D) and apparent permittivity(εr) of boundary layer capacitor depended on the amonunt(N) of seed grains. Then the relationships among these variables were investigated by using model of grain growth, and could be expressed easily using the following equation,
εr=αD=αN1/3 (α, β:coefficient).
And the apparent permittivity of boundary layer capacitor increased to 1.4 times of the original value, when the grain size was controlled with seed grains.
