Stability of BaTiO 3 Ceramics Doped with Dy for High-Voltage Capacitor Use

For a small-size high-voltage capacitor for power separation filter (PSF) use, corona noises, capacitor characteristics changes, and the life characteristics of Dy-doped BaTiO 3 ceramics have been discussed. Noises caused by corona discharges are sufficiently small to meet the PSF requirement at an applied field below 2 kV/mm. The capacitance change with time for 20 years is estimated to be -5 percent, for use at 0-85°C and below 3 kV/mm. The life of the ceramic is expected to be more than 20 years; under normal temperature and below 2 kV/mm In association with the previously reported result on Dy-doped BaTiO 3 ceramics, the PSF capacitors made from small-grained BaTiO 3 ceramics doped with 0.8 atomic percent Dy will be operated for 20 years with small corona noise, without breakdown, and with a maximum capacitance variation of +7 to -14 percent.