Unconventional magnetic properties of La1-xBaxMnO3 thin films grown on SrTiO3(100) by metalorganic aerosol deposition

Abstract

Epitaxial La1-xBaxMnO3 thin films were grown on SrTiO3(100) substrates by metalorganic aerosol deposition technique. AFM surface analysis indicates a layer-by-layer growth mode. The occurrence of Laue thickness fringes in X-ray diffraction (XRD) spectra indicates a high quality single-crystalline growth of an uniformly strained film, whereas the X-ray reflection (XRR) reveals the presence of a few unit cells layer with modified electronic density. A high metal-insulator transition temperature, TMI=335 K, as well inductive coupled plasma emission spectroscopy analysis indicate the formation of LBMO with optimal Ba doping x=0.32. However, from magnetization measurements a high Curie temperature, TC=335 K, and a low coercitive field (30 Oe) coexist with a reduced saturation magnetization (~ 3 μB/Mn) and broadened paraferromagnetic transition. The relevance of magnetic phase inhomogeneity can be further revealed from the low-temperature magnetization loops. We discuss the results within the concept of “dead magnetic layer” close to the film/substrate interface, which may lead to the coexistence of different magnetic phases in the “body” of the LBMO film.