Development of Directional Point-Focus-Beam Acoustic Microscope System

定向点聚焦束声显微镜系统的研制

基本信息

批准号：
02555083
负责人：
CHUBACHI Noriyoshi
金额：
$ 10.5万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

A practical system of directional point-focus-beam(PFB) acoustic microscope with two functions of imaging and quantitative measurements has been developed as a new research tool to characterize anisotropic materials on a microscopic scale in the VHF and UHF ranges. Directional PFB acoustic probes in the frequency range of 200-400 MHz have been developed by introducing directionality into a PFB acoustic probe, limiting excitation of leaky surface acoustic waves(LSAWs) within a narrow angle with a rectangular transducer instead of a circular transducer.It has been revealed that it is essential to take into consideration the effect of beam steering of LSAWs due to the elastic anisotropy on the transducer output of the acoustic probe in order to realize a directional PFB acoustic microscope, and to limit the region of defocusing distance near the focal point for the V(z) curve analysis.It is necessary to chose arbitrarily an imaging area and an LSAW propagation direction, for characterizing the elastic properties of anisotropic materials on a microscopic area in imaging and quantitative measurements. The mechanical and electrical systems have been developed, and the experimental procedures in measurements have been established.The system has been demonstrated for investigation of a polycrystalline sample of Mn-Zn ferrite with an average grain size of 100mum. Directional acoustic images were obtained at 225 and 375 MHz for several different propagation directions of LSAWs. Anisotropy measurements of LSAW velocity in some grains of the sample have been performed through V(z) curve analysis. Anisotropic elastic properties of each grain have been characterized both in imaging and quantitative measurements.

定向点对焦梁（PFB）声学显微镜具有两种功能的成像和定量测量功能的实用系统已被开发为一种新的研究工具，可在VHF和UHF范围内以显微镜规模表征各向异性材料。通过将方向性引入到PFB声学探针中，限制了在狭窄的角度内，限制了对向下透射剂而不是圆形的threst extection the It taughtive，在200-400 MHz的频率范围内开发了方向性PFB声探针，从而限制了在狭窄的角度内的漏出表面声波（LSAW）的激发，并以矩形的透射仪而不是圆形的thress extection the It the Itive the Itive companding the Itive vise Inctive comploinity the IT效果。为了实现定向PFB声学显微镜，并限制V（z）曲线分析焦点附近的散焦距离区域，以选择任意的成像区域和lsaw的传播方向，以表征量子材料的弹性材料，各向异性是必不可少的。已经开发了机械和电气系统，并已经建立了测量中的实验程序。该系统已被证明用于研究Mn-Zn铁素体的多晶样品，平均晶粒大小为100MUM。 LSAW的几个不同传播方向在225和375 MHz处获得定向声图像。通过V（z）曲线分析，已经进行了样品中某些晶粒中LSAW速度的各向异性测量。在成像和定量测量中都表征了每种晶粒的各向异性弹性特性。