ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

1pPA9. Elastic-constant determination of small, near-isotropic crystals using resonant ultrasound spectroscopy: New quasicrystal results.

P. S. Spoor

J. D. Maynard

Dept. of Phys., Penn State Univ., University Park, PA 16802

B. Golding

Michigan State Univ., East Lansing, MI 48824

A. R. Kortan

AT&T Bell Labs., Murray Hill, NJ 07974

If a material is very nearly isotropic, quantifying the residual anisotropy may be quite difficult using methods such as pulse superposition or neutron scattering, when only a small sample is available. However, resonant ultrasound spectroscopy using piezoelectric film transducers allows precise (<0.1%) measurement of elastic constants even on very small (<0.25 mg), fragile samples. This is of interest in the study of icosahedral quasicrystals, which should theoretically be isotropic, but have closely related phases which are crystalline. Results on several samples of quasicrystalline and cubic AlCuLi will be presented, and use of rotations of the elastic tensor and Monte Carlo style error simulations to aid in the data analysis will be discussed. [Work supported by NSF Grant No. DMR-9306791 and by ONR.]