Advancing Electron Backscatter Diffraction Characterisation Techniques with a Refined Approach to Indexing via Template Matching

通过模板匹配的精细索引方法推进电子背向散射衍射表征技术

• 批准号: 1857810
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1857810
• 关键词: Advancing; Electron; Backscatter; Diffraction; Characterisation

General overviewElectron backscatter diffraction (EBSD) is a characterisation technique used in the scanning electron microscope (SEM). EBSD allows the orientations and phases of the unit cell in a crystalline structure to be determined. Usually the patterns are indexed using a Hough transform, which can identify bands in the EBSP. The Hough, however, has shortcomings in that it doesn't take into account the finer features of the EBSP. The pattern matching approach has been introduced as a way to index EBSPs to account for the finer aspects of the pattern. ObjectivesTo implement a faster and more accurate pattern matching approach to indexing EBSPs and demonstrate applications thereof. Approach- Update the current image cross correlation to use a fast Fourier transfer- Demonstrate the updated indexing is accurate and precise enough to index real patterns- Explore phase discrimination using multi-phase materials- Demonstrate novel detector set ups using multiple detectors- Use the new set up and indexing to determine the pattern centre of an EBSPNovel content- The updated Image correlation using a fast Fourier transform applied to an EBSP- The refinement step to correct the first pass indexing- Applying this to phase discrimination- Using two direct electron detectors to collect and index two patterns simultaneouslyCurrent progress1 paper on preprint in ArXiv, currently under review in ultramicroscopy entitled " Indexing Electron Backscatter Diffraction Patterns with a Refined Template Matching Approach." This paper demonstrates the new method of indexing and the refinement.Preliminary data for proof of concept collected and analysed for phase discrimination using Zirconium hydride. Sample of meteorite to use in phase discrimination polished and ready to EBSD.Direct electron detectors tested and currently buying vacuum compatible components to use them.Stage to hold the sample and detectors currently under construction.

电子背散射衍射(EBSD)是一种用于扫描电子显微镜(SEM)的表征技术。EBSD可以确定晶体结构中单胞的取向和相。通常使用霍夫变换对模式进行索引，该变换可以识别EBSP中的波段。然而，Hough有缺点，因为它没有考虑到EBSP的更好的特性。模式匹配方法是作为索引EBSP的一种方法引入的，以说明模式的更精细方面。目的实现一种更快、更准确的模式匹配方法来索引EBSP，并展示其应用。方法-更新当前图像互相关以使用快速傅立叶变换-证明更新的索引足够准确和精确到索引真实图案-探索使用多相材料的相位辨别-演示使用多个检测器的新型探测器设置-使用新的设置和索引来确定EBSP的图案中心-使用应用于EBSP的快速傅立叶变换更新的图像相关性-修正第一遍索引的细化步骤-将其应用于相位辨别-使用两个直接电子探测器同时收集和索引两个图案当前进展1在Arxiv上预印的论文，目前正在超显微镜中进行审查，标题为“用改进的模板匹配方法索引电子背向散射衍射图”。本文介绍了新的指标化方法和改进方法。收集了用于概念验证的初步数据，并对氢化锆鉴相进行了分析。用于鉴相、抛光和EBSD的陨石样品。直接电子探测器经过测试，目前正在购买真空兼容部件以使用它们。存放样品和探测器的阶段目前正在建设中。