Antiphase boundaries in Ba0.75Sr0.25TiO3 epitaxial film grown on (001) LaAlO3 substrate

Ba0.75Sr0.25TiO3 film was epitaxially grown on a (001) LaAlO3 substrate using single-target pulsed laser deposition. The microstructure of the epitaxial film was investigated by conventional and high-resolution transmission electron microscopy. Apart from dislocations and stacking faults, two different kinds of antiphase boundaries, one being straight, and the other being zig-zagged, have been observed. The formation mechanism of these antiphase boundaries is discussed.