S. Shibagaki et al., CALCIUM-DOPING EFFECT ON TEMPERATURE COEFFICIENTS OF DIELECTRIC-CONSTANTS IN SRTIO3 CAPACITORS, Journal of Materials Science, 32(6), 1997, pp. 1449-1453
SrTiO3 ceramic capacitors were studied to improve the temperature coef
ficient, tau, of dielectric constants without decreasing the dielectri
c constants. It was indicated that an addition of calcium in an insula
ting reagent improved tau. From scanning electron microscopy and energ
y-dispersive X-ray analysis measurements, the origin of this improveme
nt was ascribed to the following layers: (1) the oxide layers which we
re formed at the grain boundaries, and (2) the bismuth-oxide layers wh
ich were formed on the sample surface.