Abstract
An ultrasonic micro-spectroscopy technique based on reflectivity measurements has been applied to the anisotropy evaluation of a spherical crystal. The reflectivity is measured using an ultrasonic micro-spectrometer with spherical-planar-pair lenses. At first, the incident angle dependence of ultrasonic reflection coefficients at small area on a water/GaAs(111) interface was successfully measured as function of the azimuthal angle lying in the (111) surface. It has been demonstrated that the anisotropy on the (111) surface can be evaluated by the simplified method proposed in this work. Then, an attempt to measure the reflectivity around the (0001) axis of a spherical crystal of 10mm in diameter has been applied. The azimuthal angle dependence of the amplitude and phase of the measured reflection coefficients are measured. The result has shown that the proposed method could be a useful for evaluating the anisotropy of small spherical crystals.
