Structure–microstructure–property relationships in lead-free BCTZ piezoceramics processed by conventional sintering and spark plasma sintering

Feres Benabdallah (1, 2) , Catherine Elissalde (2) , U-Chan Chung Seu (2) , Dominique Michau (2) , Angeline Poulon-Quintin (2) , Marion Gayot (3) , Pascale Garreta (3) , Hamadi Khemakhem (1) , Mario Maglione (2)

1 Laboratoire des Matériaux Ferroélectriques
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 PLACAMAT - Plateforme Aquitaine de Caractérisation des Matériaux

Lead-free piezoelectric ceramics belonging to the pseudo-binary system (1 − x)BaTi0.8Zr0.2O3-x Ba0.7Ca0.3TiO3(BCTZ, x = 0.32 and 0.5) were prepared using conventional sintering and spark plasma sintering. This comparative study shows how the macroscopic properties of ferroelectric BCTZ perovskites are affected when the grain size is decreased. The crystallographic structure and the microstructural characteristics are thoroughly investigated for ceramic samples obtained by both sintering methods. We clearly demonstrate that the dielectric, piezoelectric, pyroelectric and ferroelectric properties in SPS ceramics are strongly affected by the grain size and the structural defects leading to local strain fields which undermine the polarisation flexibility. This confirms that the critical compositions showing remarkably large piezoelectric coefficients are extremely sensitive to external and internal stresses.

Mots clés: Lead-free piezoceramics; Spark plasma sintering; ferroelectricity; piezoelectricity; defects

Domaines: Matériaux

Feres Benabdallah, Catherine Elissalde, U-Chan Chung Seu, Dominique Michau, Angeline Poulon-Quintin, et al.. Structure–microstructure–property relationships in lead-free BCTZ piezoceramics processed by conventional sintering and spark plasma sintering. Journal of the European Ceramic Society, 2015, 35 (15), pp.4153-4161. ⟨10.1016/j.jeurceramsoc.2015.06.030⟩. ⟨hal-01218878⟩