精确比较单晶的晶格参数
E G Kessler1, A Henins1, R D Deslattes1
1National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
概括
一个新的格子间距比较器使用布拉格角测量精确地测量了水晶格子间距差异. 这种进步实现了1×10−8的相对不确定性,验证了晶格测量.
科学领域:
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
- 计量学 计量学 计量学
背景情况:
- 精确测量格子间距对于材料的表征和标准化至关重要.
- 现有的方法在准确性和范围上可能有局限性,用于比较近乎完美的晶体的晶格参数.
研究的目的:
- 描述一个在国家标准与技术研究所 (NIST) 开发的新型格子间距比较器.
- 详细说明使用布拉格角度变化测量格子间距差异的方法.
- 评估比较器的精度和准确性,包括不确定性分析.
主要方法:
- 使用一个近乎不分散的几何形状的双晶谱仪.
- 采用了一种灵敏的异体干扰仪,用光学多边形校准,用于精确的布拉格角测量.
- 嵌入了几乎相同厚度的晶体,以利用Pendellösung振荡来进行增强的配置分析.
主要成果:
- 成功测量了来自NIST和Physikalisch-Technische Bundesanstalt (PTB) 的样本之间的格子间距差异,相对不确定性为1 × 10−8.
- 结果与在PTB和NIST独立执行的绝对格子间距测量结果一致.
- 来自和估计的不确定性组成部分,这些不确定性是由系统效应引起的,比如错位.
结论:
- 开发的格子间距比较器为测量格子参数差异提供了高精度.
- 仪器的性能验证了其在材料科学中的临界计量学应用的能力.
- 该研究为理解和减轻格子间距测量的不确定性提供了一个框架.
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