%0 Journal Article %K Deposition %K Thin films %K Transmission electron microscopy %K Ions %K Oxides %K Substrates %K Oxide films %K Lanthanum compounds %K Computer simulation %K X-ray Diffraction %K Crystal lattices %K Molecular structure %K Crystal atomic structure %K Spectrometers %K Cubic face centered cubic structure %K Energy dispersive spectrometry %K High resolution lattice images %K Perovskite structure %A H Li %A L Salamanca-Riba %A Ramamoorthy Ramesh %A J.H Scott %B Journal of Materials Research %D 2003 %G eng %I Materials Research Society %P 1698-1704 %R 10.1557/JMR.2003.0233 %T Ordering in (La,Sr)(Al,Ta)O3 substrates %V 18 %X (La, Sr)(Al, Ta)O3 (LSAT) has recently received increased attention as a substrate for the deposition of various oxide films. LSAT is usually considered as having a perovskite structure. However, the exact atomic structure of LSAT is not yet well known and has received little attention up to now. In this paper, a series of studies using x-ray diffraction, transmission electron microscopy, and energy dispersive spectrometry were conducted to determine the atomic structure of LSAT. It was found that LSAT consists of two types of domains: one with a simple cubic perovskite structure (disordered with a = 0.3868 nm) and the other with a face-centered-cubic structure (ordered with a = 0.773 nm). Computer image simulation of high-resolution lattice images suggests that the ordered structure is due to ordering of the Al and Ta ions.