Effect of SiO2 doping on the dielectric, ferroelectric and piezoelectric properties of (Ba0.7Ca0.3)(Zr0.2Ti0.8)O3 ceramics with different sintering temperatures

In the present study, the doping effect of SiO
₂
on the dielectric, ferroelectric and piezoelectric properties of the (Ba
_0.7
Ca
_0.3
)(Zr
_0.2
Ti
_0.8
)O
₃
(abbreviated as BZT-50BCT hereafter) ceramics sintered at different temperatures were systematically studied. With the SiO
₂
dopant, the distribution of the grain size became more homogeneous. Besides, the average grain sizes firstly increased with increasing the SiO
₂
concentrations and then decreased. As the macroscopic properties, the dielectric constant decreased with the addition of SiO
₂
. The remnant polarization P
_r
firstly increased and then decreased with increasing the SiO
₂
concentration. While the coercive field monotonically decreased with the SiO
₂
dopant. And the piezoelectric constant d
₃₃
firstly enhanced by the SiO
₂
and then reduced as further increasing the SiO
₂
concentrations. The maximum d
₃₃
of 500 pC/N has been obtained in the 0.5 mol% SiO
₂
doped BZT-50BCT ceramics sintered at 1500° from the industry available raw materials.