Grain size effect on the high field properties of $(\mathrm{Ba},\mathrm{Ca})(\mathrm{Ti},\mathrm{Zr}){\mathrm{O}}_3$ceramics

Lavinia Curecheriu1, Maria Teresa Buscaglia2, Giovanna Canu2, Vincenzo Buscaglia2, Liliana Mitoseriu2 1Dielectrics, Ferroelectrics& Multiferroics Group, Departament of Physics, Al.I. Cuza University, 11 Bv. Carol I, 700506, Iasi, Romania

2Institute of Condensed Matter Chemistry and Technologies for Energy ICMATE-CNR, Via de Marini 6, Genoa, Italy

One of the most promising BT-based materials for piezoelectric applications is the pseudobinary ferroelectric $(1-x)Ba\left(Z{r}_{0.20}T{i}_{0.80}\right)O_3-x\left(B{a}_{0.70}C{a}_{0.30}\right)Ti{O}_3$ (BCTZ) (x is the molar percent of BCT). In the present paper, we present high field properties (dc-tunability, piezoelectric and ferroelectric characteristics) of  $B{a}_{0.85}C{a}_{0.15}T{i}_{0.90}Z{r}_{0.10}{O}_3$ ceramics with grain size larger than 1?m. The ceramics were prepared by sintering solid state powders at different temperatures between 1400-1500°C and times (from 0.2-24 hours). The grain size of ceramics determined from SEM images were between 2 ?m for the samples sintered at 1400ºC/2h to 27 ?m for the samples obtained at 1500ºC /24h. The piezoelectric properties are dependent on the poling conditions (poling temperature and electric field) and grain size. Polarization vs. electric field (P-E) hysteresis loop study showed that exist a critical grain size (~ 9 ?m) for which the remnant and saturation polarisation is higher. The same critical size was obtained from dc-tunability investigation. The presented data provide a complete picture of the size effect dependence of the high field properties in $B{a}_{0.85}C{a}_{0.15}T{i}_{0.90}Z{r}_{0.10}{O}_3$.

Acknowledgment: The financial support of the PN III-P1-1.1-TE-2016-1951 is acknowledged.