Heteroepitaxial growth of lanthanum aluminate films derived from mixed metal nitrates

Journal Article · Thu May 01 04:00:00 EDT 1997 · Journal of Materials Research

DOI:https://doi.org/10.1557/JMR.1997.0179· OSTI ID:508968

Ng, M F; Cima, M J ^[1]

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1. Ceramics Processing Research Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

Epitaxial lanthanum aluminate (LaAlO{sub 3}) thin films were deposited on single-crystal substrates by pyrolysis of spin-on mixed nitrate precursors. The films are epitaxial without any second phase. TEM micrographs show that all of these films have pores with sizes ranging from 5 to 30 nm. Grain boundaries are not observed. Selected area diffraction shows that the films are single-crystal-like, despite the porosity. All the films are smooth and crack-free. The precursors first decompose into an amorphous mixture. Heterogeneous nucleation occurs on the lattice-matched, single-crystal substrate surface. The epitaxial films grow upward and consume the amorphous regions. The crystallization temperature of LaAlO{sub 3} is lower for thin films than for bulk samples due to nucleation on the substrate. The crystallization of LaAlO{sub 3} does not exhibit linear growth kinetics. The Johnson{endash}Mehl{endash}Avrami exponent of growth is between 1.4 to 1.5. This deviation from the linear growth model (n=1) can be attributed to continuous nucleation on the substrate/film interface. {copyright} {ital 1997 Materials Research Society.}

• OSTI ID: 508968
• Journal Information: Journal of Materials Research, Journal Name: Journal of Materials Research Journal Issue: 5 Vol. 12; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
CERAMICS
DEPOSITION
EPITAXY
LANTHANUM OXIDES
PHASE STUDIES
POROSITY
PRECURSOR
PYROLYSIS
SPIN-ON COATINGS
SUBSTRATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY