Mechanical, dielectric, ferroelectric and piezoelectric properties of 0–3 connectivity lead-free piezoelectric ceramic 0.94Bi<inf>0.5</inf>Na<inf>0.5</inf>TiO<inf>3</inf>–0.06BaTiO<inf>3</inf>/Portland cement composites

Abstract

In this research, lead-free piezoelectric ceramic 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 (BNT–BT)/Portland cement (PC) composites have been fabricated for use as sensor in structural health monitoring applications. BNT–BT ceramic particles were mixed with Portland cement using ceramic particles content of 30–60 vol.% to form 0–3 connectivity pattern BNT–BT/PC composite. The acoustic impedance, compressive strength, dielectric, ferroelectric and piezoelectric properties of the composites were investigated as a function of ceramic content. The results indicated that the BNT–BT ceramic content of ≈ 40–60 vol.% are the optimal BNT–BT ceramic contents for acoustic impedance matching between composite and concrete structure. The compressive strength was found in the region of 28.19–35.30 MPa for BNT–BT/PC composites is close to that of normal concrete. The dielectric constant (εr) value of composites increased as BNT–BT ceramic content increased, while the dielectric loss value reduced with higher BNT–BT ceramic content. The BNT–BT ceramic content in these composites has a beneficial effect on the ferroelectric behavior. Moreover, composite with BNT–BT ceramic content of 60 vol.% exhibited the highest piezoelectric coefficient (d33) value of 42 pC/N. The piezoelectric voltage coefficient (g33) of BNT–BT/PC composites was found to be in the range of 13.96 mV m/N to 17.00 mV m/N. Furthermore, the εr and d33 values of composites were close to the cubes model. According to the results, it is noted that these composites have good compatibility with concrete structure and has the potential for use as sensor in structural health monitoring applications.