Reciprocal Space Mapping of Thin La$_{x}$ Mn O$_{3}$ Films of Varying Thickness

In order to understand the growth of ultrathin manganite films on substrates, we made reciprocal space maps in the 004, 404, and 044 pseudocubic directions of La$_{x}$MnO$_{3}$ films deposited on LaAlO$_{3}$ (LAO) via metal-organic chemical vapor deposition. The x-ray maps exhibit the strain effects of the lattice-substrate mismatch and the effects of a twinned interface on the growth of films. Reciprocal space mapping provides more accurate lattice parameters and strain effects from lattice-substrate interface mismatch. A characteristic feature of the LAO substrates is twinning, which results in multiple structural components of the films, similar lattice parameters but differing orientation. These characteristics reveal crucial aspects of deposition processes to be inspected in assuring high-quality films. This research is supported by NSF DMR-0209243 and DMR-0512196.