Experimental study on elastic anistropy of mantle minerals

在本财政年度，我专注于晶体取向测量和高压相的微晶（~500μm或更小）的成形。我引入了一个CCD相机来确定X射线对小标本的位置。该系统甚至适用于其他项目。然后，我研究了适当的方法来塑造小样品，如在水中处理一个颗粒，以防止样品飞走。我准备了一个含水量为3wt%的含水β脊髓的球形样品。该晶体由Anton博士在该研究所合成，水含量由大坂市立大学的Shinoda博士使用FTIR方法测定。水合β尖晶石的晶体结构为单斜晶系。因此，为了避免数值分析的困难，我正在考虑通过应用晶体学中经常使用的空气圆形方法来制作一个球体作为样品的最终形状。本项目将是第一个利用共振超声光谱技术测量高压相单晶弹性的实例，并且在共振峰的数据分析方面取得了重要进展。利用锁相放大器检测信号相对于参考输入相移的特点，尝试了同时对真实的和虚部进行峰值拟合。我们通过在20-30 MHz左右成功地检查我们自己的数据来证实新算法的分辨率能力。结合高频共振超声光谱仪的硬件进展，我们将这一结果提交给了《科学仪器评论》。

In this fiscal year, I was concentrated on crystallographic orientation measurement and shaping of micro crystal (~500μm or less) of high pressure phases. I introduced a CCD camera to determine X ray position against the small specimen. This system works well even for other projects. Then, I examined appropriate way to shape small specimen, such as treating a grain in water to prevent the specimen flown away.I am preparing a sphere specimen of hydrous β spinal with 3wt% water. This crystal was synthesized by Dr. Anton in this institute, and the water content was determined by Dr. Shinoda at Osaka City University by using FTIR method. The crystal structure of hydrous β spinal is monoclinic. Thus to avoid numerical analysis difficulty, I am considering to make a sphere for the final shape of the specimen by applying the air-round method frequently used in crystallography. This project will be the first example of resonant ultrasound spectroscopy to measure single crystal elasticity of high pressure phases.Furthermore, we made important progress on data analysis of resonant peaks. With utilizing the specialty of lock-in amplifier detecting signal phase shift against reference input, we tried to peak fitting simultaneously on real and imaginary parts. We confirmed the resolution ability of the new algorithm by examining our own data at around 20-30 MHz successfully. We submitted the result, combined with the hardware progress of high frequency resonant ultrasonic spectroscopy, to Review of Scientific Instruments.