Structure and defect characterization of multiferroicReMnO3 films and multilayers by TEM

Abstract

Epitaxial rare earth manganite thin films (ReMnO3;Re = Tb, Ho, Er, and Y) and multilayers were grown by liquid injection metal organicchemical vapor deposition (MOCVD) on YSZ(111) and the same systems were grownc-oriented on Pt(111) buffered Si substrates. They have been structurally investigated byelectron diffraction (ED) and high resolution transmission electron microscopy(HRTEM). Nanodomains of secondary orientation are observed in the hexagonalYMnO3 films. They are related to a YSZ(111) and Pt(111) misorientation.The epitaxial film thickness has an influence on the defect formation.TbO2 andEr2O3 inclusions areobserved in the TbMnO3 and ErMnO3 films respectively. The structure and orientation of these inclusions are correlated to theresembling symmetry and structure of film and substrate. The type of defect formed in theYMnO3/HoMnO3 andYMnO3/ErMnO3 multilayers is also influenced by the type of substrate they are grown on. In our work,atomic growth models for the interface between the film/substrate are proposed andverified by comparison with observed and computer simulated images.