Quantitative evaluation of scale-parameter on material properties by an ultrasonic micro-spectrometer with a high apatial resolution

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An ultrasonic micro-spectrometer (UMSM) with a high spatial resolution was developed in order to evaluate scale-parameters which are related to material properties. The UMSM developed here is expected to be useful for the materials characterization by ultrasonic spectroscopy at a small area on the materials surface. The results obtained in this work are summarized as follows :1) The UMSM enables us to measure precisely the reflection coefficients of materials at a small area in the frequency range from 10 to 150 Mhz ; (2) Using the measured reflection coefficients we can precisely determined phase velocities and attenuation factors of acoustic surface waves which are closely related to mechanical and electrical properties of materials. Elastic properties and grain size of materials are quantitatively estimated from the surface wave velocities and the attenuations, respectively, and also anisotropy can be detected from the reflection coefficients ; (3) An inversion technique based on th … More e ultrasonic reflectivity measurement was proposed for quantitatively estimating elastic properties of caoting films on substrate. This inversion enables us to determined materials properties of the thin film composite with randomly dispersed inclusions ; (4) Mean reflection coefficients on liquid-polycrystals interface are newly proposed for quantitatively estimating mean properties of inhomogeneous materials, and are examined experimentally and numerically. It was confirmed that the mean reflection coefficient defined here should be available as a useful parameter for estimating the local average properties in inhomogeneous materials as well as polycrystalline materials. The scale parameter on elastic properties of materials may also be estimate effectively by the mean reflection coefficient.Because the spatial resolution and frequency characteristic in the reflectivity measurements can easily be improved by reconstructing the UMSM,efficient measurements for estimating the scale parameter will be performed in near future. Less