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Ca,Zr doped barium titanate (Ba,Ca)(Ti,Zr,Ca)O3 is a potential
dielectric material that meets the need of Y5 and Z5 capacitors
in MLC technology. So the purposes of this study were to
evaluate the effect of Ca,Zr dopants on the sintering behavior
and the dielectric properties.It is found that Ca(Ti site)
dopant enhance the sintering and reduce the sintering activation
energy from 1460kJ/mole (pure BaTiO3) to 800kJ/mole .The powders
prepared by citric process will be densified at lower
temperature than that by solid state reaction. The Ca(Ba site)
dopant raise the sintering temperature at the liquid-enhanced
sintering behavior but the preparation method ,the powder
particle size ,and the green density have no obvious effect on
liquid enhanced sintering .The CaTi ,ZrTi dopants affect the
dielectric properties strongly .Both of them reduce the
tetragonal-cubic phase transition temperature (Tc) and broaden
the phase transition but Ca(Ti site) dopant reduces the
dielectric constant and ZrTi dopant raises it. When Ca(Ti site)
,Zr dopants exist simultaneously ,the effect is stronger than
the summation of them. The difference on dielectric constant of
Ca(Ti site) doped BaTiO3 that prepared by different method may
be related to the homogeneity of Ca(Ti site) dopant. We discuss
the internal stress model about the movement of Tc ,too ,and we
find it can not explain our result . We find a special
phenomenon called dielectric unstableness near phase transition
point at high frequency .The dielectric - temperaturerelation of
barium titanate based materials will be unstable near the phase
transition at frequency > 500 kHz ,but we can't observe the same
phenomenon at CaTi doped BaTiO3 specimen .It may be related to
the homogeneity of CaTi dopant,too . The long batch time of
ball-mill in processes will affect the sintering behavior and
dielectric properties ,and the preparation method f Zr solution
in citric process were reported ,too .
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