Influence of substrate temperature on morphological and ferroelectric properties of Ba0.75Sr0.25TiO3 thin films deposited on nichrome substrates by Rf sputtering

Ba0.75Sr0.25TiO3 (BST) thin films have been deposited by Rf-sputtering on nichrome substrates that have been heated in the range from 400 °C to 747 °C. The films were characterized morphologically and ferroelectrically. The microstructure of thin films was observed using an atomic force microscope to determine rugosity and grain size. The growth of grain size observed was 75 nm and 95 nm at substrate temperatures from 549 °C to 747 °C, respectively. The ferroelectric properties were determined by hysteresis loops applying an electric field of 110 kV/cm. The films grown at substrate temperatures from 549 °C to 747 °C show a decrease of the remnant polarization P r, from View the MathML source9.87μC/cm2 to View the MathML source2.23μC/cm2, and of the coercive field strength Ec, from 59.75 kV/cm to 19.86 kV/cm. The films deposited on nichrome had uniform grain size distribution and relatively low surface roughness.