Layered microdomains and columnar grains in epitaxial La₀.₇Ca₀.₃MnO₃ films and Y₀.₇Ca₀.₃MnO₃/La₀.₇Ca₀.₃MnO₃ multilayers

Abstract

Epitaxial La₀.₇Ca₀.₃MnO₃ thin film and [Y₀.₇Ca₀.₃MnO₃/La₀.₇Ca₀.₃MnO₃]₁₀ multilayers of about 140 nm in thickness were grown by pulsed laser deposition on (001)LaAlO₃. Their microstructures were investigated by transmission electron microscopy and associated techniques. It was found that both the film and the multilayers contain an almost defect-free layer near the substrate, followed by columnar grain grown. The columns were separated by strained regions in the top layer. No interfacial dislocations were observed at either of the La₀.₇Ca₀.₃MnO₃/LaAlO₃ or the Y₀.₇Ca₀.₃MnO₃/La₀.₇Ca₀.₃MnO₃ interfaces. Interestingly, both the epitaxial film and the multilayers exhibited layered crystallographic domains. The formation mechanisms of the layered domain structures observed are discussed.