Ultrasonic Microspectroscopy of Ultra-High-Quality Synthetic a-Quartz

利用线聚焦束（LFB）和平面波（PW）超声材料表征（UMC）系统，建立了用于体声波（BAW）和表面声波（SAW）器件的合成α-石英晶体的超声显微光谱评价技术，并精确测量了晶体的声学物理常数。本研究的目的是为工业和科学领域的合成α-石英提供一个新的全球性指南和标准。提高了LFB超声材料表征系统和体超声光谱系统的测量精度. 32类晶体声学物理常数测定新方法的发展及合成和天然α-石英声学物理常数的测定：（1）发展了一种能准确测定32类晶体声学物理常数各独立分量的体声波法。这种方法需要测量长度 ...更多信息 重力和剪切速度，介电常数和密度，使用X-，Y-和Z-切标本和几个旋转Y-切标本。对SAW级合成α-石英进行了论证。结果提供了BAW速度在±0.2 m/s（±0.004%）精度范围内的常数。(2)为了比较天然和合成α-石英之间的声学特性，使用X-、Y-和Z-切割试样测量纵向和剪切速度以及LSAW速度。所有的速度差都在1.00 m/s以内，并且澄清了天然石英的声学物理常数与合成石英的声学物理常数非常相似。(3)本文提出了用LFB/PW UMC系统测量X、K和Z三种主要切割试样的LSAW速度和BAW速度，从而确定32类晶体全部常数的另一种新方法。该方法已应用于天然α-石英的测定。(4)利用本文提出的体声波法，还精确测定了天然石英的常数. BAW速度。测量了几种不同生长条件的人工α-石英晶体锭的LSAW声速、密度和晶格参数。检测到轻微的速度差异。与杂质浓度，特别是OH含量相关的速度变化对于传播方向和传播模式是不同的。晶格常数a是恒定的，但c随着OH含量的增加而变大。少

Ultrasonic microspectroscopy technology, using the line-focus-beam (LFB) and plane-wave (PW) ultrasonic material characterization (UMC) system, has been applied to establish evaluation techniques for synthetic α-quartz crystals for bulk acoustic wave (BAW) and surface acoustic wave (SAW) devices and to accurately measure the acoustical physical constants. The purpose of this study was to provide a new, worldwide guideline and standard for synthetic α-quartz in the industrial and scientific fields.1. Measurement accuracies of the LFB ultrasonic material characterization system and bulk ultrasonic spectroscopy system have been improved.2. Development of new methods for determining the acoustical physical constants of class-32 crystals and determination of the constants of synthetic and natural α-quartz:(1) A new BAW method to accurately determine all of the independent components of the acoustical physical constants for class-32 crystals was developed. This method requires to measure lon … More gitudinal and shear velocities, dielectric constants, and density, using X-, Y-, and Z-cut specimens and several rotated Y-cut specimens. The demonstration was conducted for SAW-grade synthetic α-quartz. The results provided the constants that give BAW velocities within an accuracy of ±0.2 m/s (±0.004%).(2) To compare the acoustic properties between natural and synthetic α-quartz, longitudinal and shear velocities, and LSAW velocities were measured using X-, Y-, and Z-cut specimens. All the velocity differences were within 1.00 m/s, and it was clarified that the acoustical physical constants of the natural quartz, were, very similar to those of synthetic quartz.(3) Another new method for determining all the constants for class-32 crystals by measuring LSAW velocities in addition to BAW velocities for there principal X-, K and Z-cut specimens using the LFB/PW UMC system was developed. This method was applied for natural α-quartz.(4) Precise values of the constants for natural quartz were also determined using the BAW method developed here.3. BAW velocities. LSAW velocities, density and lattice parameters were measured for the specimens prepared from several synthetic α-quartz crystal ingots with different growth conditions. Slight velocity differences were detected. The velocity changes related to the impurity concentration, especially OH content, were different for the propagation directions and propagation modes. Lattice constant a was constant, but c became larger as the OH content became higher. Less