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SrTiO3 films on platinized (0001) Al2O3: Characterization of texture and nonstoichiometry accommodation

Published online by Cambridge University Press:  03 March 2011

Dmitri O. Klenov ,
Troy R. Taylor  and
Susanne Stemmer
Dmitri O. Klenov*
Affiliation:
Materials Department, University of California, Santa Barbara, California 93106-5050
Troy R. Taylor
Affiliation:
Materials Department, University of California, Santa Barbara, California 93106-5050
Susanne Stemmer
Affiliation:
Materials Department, University of California, Santa Barbara, California 93106-5050
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Transmission electron microscopy and x-ray diffraction were used to study SrTiO3 films grown on platinized (0001) Al2O3 substrates. The Pt films were epitaxial with an orientation relationship described by (111)Pt‖(0001)Al2O3 and [110]Pt‖[10¯10]Al2O3. SrTiO3 films with two different Sr to Ti ratios, 1.02 and 1.4, were deposited by radio-frequency magnetron sputtering. In the film with a large amount of Sr excess, the grain sizes were smaller and a high density of planar defects was observed. The films were predominantly (111) textured, but a weaker (110) texture component was also found, independent of stoichiometry. While the (111) texture could be explained with the excellent lattice match with (111) Pt, the (110) textured grains had a large mismatch with the Pt electrode. We propose that the presence of the (110) oriented grains is due to nucleation at Pt surface defects. Planar defects in the films with a large amount of Sr excess served to accommodate the nonstoichiometry. Comparison with homoepitaxial SrTiO3 films showed that the density of planar defects in the SrTiO3 films on (111)Pt/Al2O3 is insufficient to accommodate all the excess Sr. The influence of the film microstructure on the dielectric properties is also discussed.

Keywords

TextureTransmission electron microscopy (TEM)Thin film
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 5 , May 2004 , pp. 1477 - 1486
Copyright
Copyright © Materials Research Society 2004

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