Line-Focus Acoustic Microscopy Measurements of Nb2O5/MgO and BaTiO3/LaAlO3 Thin-Film/Substrate Configurations

Y.-C. Lee, J. D. Achenbach, M. J. Nystrom, S. R. Gilbert, B. A. Block, and B. W. Wessels

ABSTRACT Line-focus acoustic microscopy has been used to measure the phase velocities of surface acoustic waves on bare MgO and bare LaAlO3, and on Nb2O5/MgO and BaTiO3/LaAlO3 thin-film/substrate configurations. The thin films are polycrystalline materials. The substrates are anisotropic single-crystals. The measured angular variation of the surface acoustic wave velocities has been used to determine the elastic constants of MgO substrate and Nb2O5 thin-film. It has been assumed that the Nb2O5 films may be considered as essentially isotropic. The measurements for LaAlO3 and BaTiO3/LaAlO3 show anomalies which are attributed to twinning in the LaAlO3 substrate.

© 1995, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.

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