Ordering in (La,Sr)(Al,Ta)O3 substrates

Publication Type:

Journal Article

Authors:

H. Li; L. Salamanca-Riba; Ramamoorthy Ramesh; J.H. Scott

Source:

Journal of Materials Research, Materials Research Society, Volume 18, Number 7, p.1698-1704 (2003)

Keywords:

Computer simulation, Crystal atomic structure, Crystal lattices, Cubic face centered cubic structure, deposition, Energy dispersive spectrometry, High resolution lattice images, ions, lanthanum compounds, Molecular structure, oxide films, oxides, Perovskite structure, Spectrometers, substrates, thin films, transmission electron microscopy, X ray diffraction

Abstract:

(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.

Notes:

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