Impact of oxygen ambient on ferroelectric properties of polar-axis-oriented CaBi4Ti4O15 films

Polar-axis oriented CaBi4Ti4O15 (CBTi144) films were fabricated on Pt foils using a complex metal alkoxide solution. The oxygen ambient during crystallization of the films impacted the crystal perfection, crystallite size, and the ferroelectric properties. The 500 mm thick film crystallized in oxygen flow had single columnar structure and in-plane grain size of about 200 nm. The Scherrer's crystallite diameter was calculated as about 110 nm. The ferroelectric properties were improved. The Pr and Ec of the film enhanced as 33.6 mu C/cm(2) and 357 kV/cm, respectively, at an applied voltage of 50 V. Voltage applied for full polarization switching was lowered by controlling oxygen stoichiometry of the film. Indeed, the polar-axis-oriented CBTi144 films would open up possibilities for devices as Pb-free ferroelectric materials. (C) 2005 American Institute of Physics.