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Microstructure and Dielectric Properties of Textured SrTiO 3 Thin Films
Author(s) -
Schmidt Steffen,
Lu Jiwei,
Keane Sean P.,
Bregante Lia D.,
Klenov Dmitri O.,
Stemmer Susanne
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00195.x
Subject(s) - materials science , microstructure , dielectric , texture (cosmology) , sputter deposition , thin film , composite material , curie temperature , strontium titanate , sapphire , condensed matter physics , sputtering , optics , nanotechnology , optoelectronics , ferromagnetism , laser , image (mathematics) , physics , artificial intelligence , computer science
We investigate the relationship between microstructure and dielectric properties of textured SrTiO 3 thin films deposited by radio‐frequency magnetron sputtering on epitaxial Pt electrodes on sapphire substrates. The microstructures of Pt electrodes and SrTiO 3 films are studied by transmission electron microscopy, atomic force microscopy, and X‐ray diffraction. SrTiO 3 films grown on as‐deposited and annealed Pt electrodes, respectively, consist of a mixture of (111)‐ and (110)‐oriented grains. Temperature‐dependent dielectric measurements show that differences in texture and microstructure are reflected in the Curie–Weiss behavior of the SrTiO 3 films. Phenomenological models that account for the effects of thermal mismatch strain on the dielectric behavior are developed for different film textures. The models predict that at a given temperature, paraelectric (111)‐oriented films of SrTiO 3 on tensile substrates will have a higher Curie–Weiss temperature and a greater dielectric constant than (110)‐oriented films or bulk SrTiO 3 . The experimental dielectric behavior is compared with the predictions from theory, and different contributions, such as interfacial layers, film stress, and microstructure, to the Curie–Weiss behavior are discussed.