Enhanced ferroelectric and piezoelectric properties of (1-x)BaZr0.2Ti0.8O3-xBa0.7Ca0.3TiO3 thin films by sol-gel process

Lead free (1-x)BaZr0.2Ti0.8O3-xBa0.7Ca0.3TiO3 (BZT-xBCT) thin films were successfully deposited on Pt/Ti/SiO2/(100)Si substrates via the sol-gel process. Both structural and electric properties of the thin films demonstrated the strong composition dependence. The BZT-xBCT thin film with x = 0.3 exhibited excellent electric properties with a large piezoelectric coefficient, d33 of 280 pm/V and a high remnant polarization, Pr of 12 μC/cm2. The enhanced ferroelectric and piezoelectric properties of BZT-xBCT thin films were primarily attributed to the composition close to the triple point of the morphotropic phase boundaries (MPB) system, where the coexisting of rhombohedral and tetragonal phases takes place.