Dependence of excess bismuth content in precursor sols on ferroelectric and dielectric properties of Bi3.25La0.75Ti3O12 thin films fabricated by chemical solution deposition

Bi3.25La0.75Ti3O12 (BLT) thin films were fabricated on Pt/Ti/SiO2/Si(1 0 0) substrates by chemical solution deposition (CSD), and the dependence of ferroelectric and dielectric properties of the as-deposited BLT thin films on excess Bi content in precursor sols was studied. It is found that the prepared BLT thin film shows the best polarization–electric field, capacitance–voltage and dielectric constant (er)–frequency characteristics, when the value of excess Bi content in precursor sols is 10%. In detail, its remnant polarization (2Pr) value is 40 mC/cm2, the capacitance tunability is 21% measured at room temperature under conditions of an applied voltage of 8 Vand measurement frequency of 10 kHz, and the er is 696 at 100 kHz frequency