Title :
Line-focus acoustic microscopy measurements of Nb/sub 2/O/sub 5//MgO and BaTiO/sub 3//LaAlO/sub 3/ thin-film/substrate configurations
Author :
Lee, Y.-C. ; Achenbach, J.D. ; Nystrom, M.J. ; Gilbert, S.R. ; Block, B.A. ; Wessels, B.W.
Author_Institution :
Center for Quality Eng. & Failure Prevention, Northwestern Univ., Evanston, IL, USA
fDate :
5/1/1995 12:00:00 AM
Abstract :
Line-focus acoustic microscopy has been used to measure the phase velocities of surface acoustic waves on bare MgO and bare LaAlO/sub 3/, and on Nb/sub 2/O/sub 5//MgO and BaTiO/sub 3//LaAlO/sub 3/ 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 Nb/sub 2/O/sub 5/ thin-film. It has been assumed that the Nb/sub 2/O/sub 5/ films may be considered as essentially isotropic. The measurements for LaAlO/sub 3/ and BaTiO/sub 3//LaAlO/sub 3/ show anomalies which are attributed to twinning in the LaAlO/sub 3/ substrate.<>
Keywords :
acoustic materials; acoustic microscopy; barium compounds; dielectric thin films; elastic constants; lanthanum compounds; magnesium compounds; niobium compounds; surface acoustic waves; twinning; BaTiO/sub 3/-LaAlO/sub 3/; Nb/sub 2/O/sub 5/-MgO; anisotropic single-crystals; elastic constants; line-focus acoustic microscopy; phase velocities; polycrystalline materials; surface acoustic waves; thin-film/substrate configurations; twinning; Acoustic measurements; Acoustic waves; Anisotropic magnetoresistance; Microscopy; Niobium; Phase measurement; Substrates; Surface acoustic waves; Transistors; Velocity measurement;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
