Suppression of antiphase domain boundary formation in Ba0.5Sr0.5TiO3 films grown on vicinal MgO substrates

Abstract

Ba 0.5 Sr 0.5 TiO 3 (BST) thin films were epitaxially grown on MgO vicinal substrates by pulsed-laser deposition and molecular-beam epitaxy. [001] oriented MgO substrates with 2° and 5° miscut toward [010] were selected. The nucleation of antiphase domain boundaries in the direction parallel to the step edges is greatly reduced in BST films grown on the vicinal substrates compared to the films grown on flat substrates. The reduction in antiphase domain boundaries gives rise to a higher dielectric constant when the electrodes are parallel to the direction of the steps, by about 280–460, than in the perpendicular direction.