Grain size effect on piezoelectric properties of BaTiO3 ceramics

Abstract

We demonstrated the grain size effect on piezoelectric properties of pure BaTiO3 ceramics. BaTiO3 ceramics with various grain sizes were prepared by conventional and two-step sintering methods. The piezoelectric strain constant d33 increased with decreasing grain size when the grain size was more than 1.2 µm, whereas it decreased when the grain size was below 1.2 µm. The maximum d33 was 460 pC/N, which is approximately three times larger than that of coarse BaTiO3 ceramics. The increase in d33 was well explained by the domain-wall contribution, while the decrease in d33 was understood as the grain boundary effect. On the other hand, the piezoelectric voltage constant g33 increased with decreasing grain size down to 0.6 µm. The piezoelectric constants d33 and g33, and the mechanical quality factor Qm can be controlled by the grain size of BaTiO3 ceramics.