AVS 45th International Symposium
    Applied Surface Science Division Monday Sessions
       Session AS-MoP

Paper AS-MoP5
The Orientational Relationship in Epitaxial Rocksalt(001)/Rocksalt(001) and Rocksalt(001)/Perovskite(001)

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Aspects of Applied Surface Science Poster Session
Presenter: G. Chern, National Chung-Cheng University, Taiwan
Authors: G. Chern, National Chung-Cheng University, Taiwan
C. Cheng, National Cheng Kung University, Taiwan
Correspondent: Click to Email
We have grown several different oxide thin films, including MgO, SrO, NiO, and Fe@sub 3@O@sub 4@ on single crystalline MgO(001) and SrTiO@sub 3@(001) substrates by molecular beam epitaxy. These oxides have either rocksalt or perovskite structure which are two of the most standard crystalline structures in ionic crystals. By using high energy electron diffraction (RHEED) we observed some specific orientation relations between these two structures. The interface of a rocksalt/rocksalt only shows a direct matching configuration. However, the interface of rocksalt(001)/perovskite(001) shows at least two different matching configurations, direct on and 45-degree rotation of the film relative to the substrate. These results imply:(1) SrTiO@sub 3@ (or other perovskite substrate) is a "better" substrate candidate for a hetero-epitaxial thin film growth. The grown material may or may not need to be closely lattice matched to the substrate because there are two stable interface matching possibilities for an epitaxial growth. (2) Since the matching configurations are originated from the interfacial energy, a simple "electrostatic matching" instead of "geometrical matching" may be constructed for the ionic systems with different structures.