Ferroelectric properties of barium titanate thin films grown on nichrome substrates by RF sputtering

BaTiO3 thin films were grown on nichrome substrates by radio frequency (RF) sputtering, and their structural and ferroelectric properties were measured and compared with those deposited on Pt/TiO2/SiO2/Si substrates under the same conditions. The films were sputtered in an off-axis geometry at room temperature. After deposition, the films were annealed. The thickness, chemical composition, microstructure and ferroelectric properties of the films were determined. The results suggest that nichrome is not only a suitable electrode-substrate for growing ferroelectric BaTiO3 films but also improves the ferroelectric properties. Larger remanent polarisations, 5.4 microcoulomb/cm2, with coercive fields of about the same magnitude, 200 kV/cm, can be obtained. This is because the substrate used does not lead to cracking in the films.