Microstructure of TiO sub 2 rutile thin films deposited on (11 2 0). alpha. --Al sub 2 O sub 3

Journal Article · Fri Nov 01 00:00:00 EST 1991 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1991.2417· OSTI ID:6257057

Gao, Y; Merkle, K L; Chang, H L.M.; Zhang, T J; Lam, D J ^[1]

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1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois (USA)

TiO{sub 2} rutile thin films grown on (11{bar 2}0) sapphire ({alpha}--Al{sub 2}O{sub 3}) by the MOCVD technique have been characterized by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). The TiO{sub 2} rutile thin films grew on the sapphire with two epitaxial orientations. The epitaxial orientation relationships between the rutile films (R) and the sapphire substrate (S) were found to be (1) (101)(010){sub R}{parallel}(11{bar 2}0)(0001){sub S} and (2) (200)(010){sub R}{parallel}(11{bar 2}0)(0001){sub S}. Detailed atomic structures of near-interface regions have been investigated by HREM, providing a clear picture of the initial stage of film growth. HREM images show that about 70% of the nuclei at the interface are the (101) rutile, but most of them are very small, about 5 nm (or 2% of the film thickness) in the growth direction. The film growth was dominated by the (200) orientation. Nucleation and growth of the films will be discussed in terms of the lattice mismatch at the interface and growth rates along the two orientations. Planar defects such as twin boundaries and special grain boundaries are commonly observed in the films, especially in regions close to the substrate. The twin plane and twinning direction are {l brace}101{r brace} and {l angle}101{r angle}, respectively. Special grain boundaries are found to be correlated with nucleation and twinning.

• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 6257057
• Journal Information: Journal of Materials Research; (United States), Vol. 6:11; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TITANIUM OXIDES
CHEMICAL VAPOR DEPOSITION
MICROSTRUCTURE
ALUMINIUM OXIDES
ELECTRON MICROSCOPY
EPITAXY
GRAIN BOUNDARIES
RUTILE
THIN FILMS
TWINNING
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
CRYSTAL STRUCTURE
DEPOSITION
FILMS
MATERIALS
MICROSCOPY
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
SURFACE COATING
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies