How heteroepitaxy occurs on strontium titanate.

Author(s) Cook, S.; Letchworth-Weaver, K.; Tung, I.C.; Andersen, T.K.; Hong, H.; Marks, L.D.; Fong, D.D.
Journal Sci Adv
Date Published 2019 Apr
Abstract

In traditional models of heteroepitaxy, the substrate serves mainly as a crystalline template for the thin-film lattice, dictating the initial roughness of the film and the degree of coherent strain. Here, performing in situ surface x-ray diffraction during the heteroepitaxial growth of LaTiO on SrTiO (001), we find that a TiO adlayer composed of the 33.7° and 45.0° reconstructions is a highly active participant in the growth process, continually diffusing to the surface throughout deposition. The effects of the TiO adlayer on layer-by-layer growth are investigated using different deposition sequences and anomalous x-ray scattering, both of which permit detailed insight into the dynamic layer rearrangements that take place. Our work challenges commonly held assumptions regarding growth on TiO-terminated SrTiO (001) and demonstrates the critical role of excess TiO surface stoichiometry on the initial stages of heteroepitaxial growth on this important perovskite oxide substrate material.

DOI 10.1126/sciadv.aav0764
ISSN 2375-2548
Citation Cook S, Letchworth-Weaver K, Tung I-, Andersen TK, Hong H, Marks LD, et al. How heteroepitaxy occurs on strontium titanate. Sci Adv. 2019;5(4):eaav0764.

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