Dielectric properties and microstructure of (Sr.Ca)TiO/sub 3/-based boundary layer capacitor materials

The dielectric properties and the microstructure of (Sr.Ca)TiO/sub 3/-based boundary layer (BL) capacitor materials were investigated. (Sr.Ca)TiO/sub 3/-based compositions were fired at 1350/spl deg/C in a N/sub 2/ atmosphere to get the base semiconducting ceramics. The metal oxides of CuO were printed on the semiconducting ceramics and fired at 1200/spl deg/C for the subsequent grain boundary diffusion. The grain size of the semiconducting ceramics was 20/spl sim/40 /spl mu/m and the apparent permittivity of the resulting material varied between 2/spl times/10/sup 4/ and 3/spl times/10/sup 4/.<
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