  Lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) ceramics had attracted much
attention for the fabrication of microelectronic devices by virtue of their
excellent dielectric, ferroelectric and piezoelectric properties. To understand
the effects of both mean grain size and grain size distribution on the
dielectric properties of lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT)
ferroelectric relaxors, an original method was proposed. It is based on the
surfactant-assisted solvothermal processing coupled with low-temperature
conventional sintering at 1250 {\deg}C. In this way, three highly dense BCZT
with different mean grain size and dissimilar grain size distribution were
designed. A significant increase of dielectric properties was obtained by a
control of grain size and densification process. The dielectric constants
measured were ranged from 5370 to 9646 and the dielectric loss was enhanced by
70%. Surprisingly, it was evidenced that there is unequivocal link between mean
grain size with dielectric properties. Indeed, it was found that the presence
of high density of refined grains leads to an improvement of dielectric
properties due to an enhancement of densification. This work may provide a new
strategy to design ferroelectric materials with enhanced properties.
