Journal of Crystal Growth 237–239 (2002) 269–273 AtomicandelectronicstructureoftheLiF/LiBr(001)interface Masao Katayama a, *, Manabu Kiguchi b , Koichiro Saiki b , Atsushi Koma a a Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan b Department of Complexity Science and Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan Abstract Heteroepitaxial growth of LiF on LiBr or NaCl has been investigated by using reflection high-energy electron diffraction,Augerelectronspectra,electronenergylossspectraandultravioletphotoelectronspectra.InthecaseofLiF on LiBr, [100] axis of LiF is parallel to [110] axis of LiBr, while LiF grows on NaCl with [100] LiF 8[100] NaCl . The azimuthal rotation of the film relative to the substrate has not been observed in other alkali halide heterostructures. The 451 rotation seems to come from two factors, the difference in lattice constants and the difference in ionic radii. The former is considered to relate to lateral matching, while the latter with vertical matching. A new loss peak was observed at about 7eV only for LiF/LiBr. The new loss peak seems to reflect the electronic state of the pseudo-LiBr molecule formed at the LiF/LiBr interface. r 2002 Elsevier Science B.V. All rights reserved. PACS: 61.14.Hg; 68.35.p; 73.20.r Keywords: A1. Interface; A3. Molecular beam epitaxy; B1. Halides 1. Introduction Recent development of molecular beam epitaxy (MBE) technique has made it possible to produce various heterostructures, which show a lot of interesting phenomena in the field of both basic and technological researches. Most of the previous studies on MBE dealt with semiconductors and metals, which have technological application. Although ionic bond is one of the basic chemical bonds, fewer studies have been done on ionic compounds, because insulating ionic materials with wide band gaps are considered to be less useful for electronic and optical devices. Alkali halides are typical ionic crystals. There- fore, the elucidation of the growth mechanism of alkali halides leads to an understanding of the growth behavior of other complex ionic com- pounds. Since the late 1980s, epitaxial growth of an alkali halide on a foreign alkali halide has been investigated by Yang and Flynn [1,2] and our group [3], and significant features are elucidated [4]. First, the film grows epitaxially on foreign alkali halides in spite of a large misfit. Second, the growthmodedependsonthelatticemisfit;layerby layer for small misfit and island growth for large misfit. Finally, the epitaxial orientation is uniquely determined, [100] film 8 [100] substrate . In the present work, we have examined hetero- epitaxial growth of LiF on LiBr or on NaCl grown on GaAs(001) or Si(001) substrates. LiBr and NaCl are known to grow epitaxially on semiconducting substrates such as GaAs(001) *Corresponding author. Tel./fax: +81-3-5841-8867. E-mail address: katayama@chem.s.u-tokyo.ac.jp (M. Katayama). 0022-0248/02/$-see front matter r 2002 Elsevier Science B.V. All rights reserved. PII:S0022-0248(01)01885-1