1分析电镜.ppt

1、近 代 材 料 分 析 方 法,绪 论,目的：1 结构 形貌 成分 位向 原子 电子态 2 实验方法 阅读文献 内容： 分析型电镜 高分辨 扫描隧道显微镜 场离子显微镜 三维原子探针 俄歇谱仪 EBSD 穆斯堡尔谱仪 正电子谱仪 X射线光电子谱仪 原理 仪器结构 应用实例,参考文献：,材料物理现代研究方法 马如璋 现代分析技术 陆家和 透射电子显微学 孟庆昌 电子显微分析实用方法 吴杏芳 Transmission Electron Microscopy -Applications in Materials Science Xiao-Feng Zhang Electron Microscopy

2、of Nanotubes 材料评价的分析电子显微方法 进藤 大辅 材料评价的高分辨电子显微方法 进藤 大辅 材料分析测试方法 黄新民 高分子物理近代研究方法 张俐娜 近刊论文,第一章 分析型电子显微镜,分 析 电 镜,STEM方式 衍射（纳米束衍射） CBED会聚束衍射 EDS分析能谱分析 EELS分析损失谱分析（能量过滤）,STEM光路图,一、STEM模式,散射体积,能损谱-能谱空间分辨率比较,二、衍射和纳米束衍射,衍射光路图聚焦束,衍射光路图摇摆束,检测器,衍射和纳米束衍射的特征,选区衍射误差 衍射花样标定相同 衍射斑点强度变化孪晶和变形,三、CBED会聚束衍射,CBED形成模式,会聚束衍

3、射盘,高阶劳厄带HOLZ线,会聚束衍射花样HOLZ线,高阶劳厄带,HOLZ线的形成,HOLZ线指数标定,常规花样 小CBED花样（L=30-50cm） 000 hkl盘（L=120-300cm） 标定常规花样 对比确定衍射盘指数,HOLZ线分裂测量柏氏矢量 不分裂,点阵常数测定,（立方系） N=1，2,会聚角的测量,会聚角的测量,测量偏离矢量、消光距离,K-M线,测量偏离矢量S和消光距离,其它：晶体点群,萃取复型试样/STEM,Determination of lattice parameters from multiple CBED patterns: A statistical appro

4、ach,Ultramicroscopy Volume 110, Issue 4,In the first part of this work, the objectives are to assess what could be the probability distribution of the random errors made in the lattice parameter measurements from a single CBED pattern, and to give an estimate of the systematic error. In the second p

5、art, the possibility of reducing the random error by using a statistical approach for the determination of the lattice parameters from multiple patterns is considered. To carry out the study a large number of diffraction patterns were acquired. Fig. 2 shows the location of twenty diffraction pattern

6、s used in our analysis. They were obtained for alpha tilt angles between 24 and +24 from the same area of the silicon single crystal at 93K. Particular tilt angles and the corresponding (approximate) zone axes are listed in Table 2. The table shows that no low-index zone axes (for which dynamic effe

7、cts are stronger) were used.,This work is devoted to the analysis of the uncertainty in lattice parameter measurements by CBED and to methods of decreasing it. The analysis of a large number of diffraction patterns acquired from a high purity silicon sample at 93K with the CBED technique indicates t

8、he presence of both types of errors: random and systematic. The random error follows the normal distribution, and the relative standard deviation is about 34104 for lattice parameter measurements made from one single pattern with a LaB6 TEM without energy filter. The main systematic error apparently

9、 comes from the determination of the actual voltage. Actually, it is a random error with normal distribution. It appears as a systematic error only because of the experimental protocol according to which the same actual voltage value is assigned for all patterns acquired in a session. It is shown th

10、at both random and apparent systematic errors can be reduced by a statistical approach based on multiple patterns. The accuracy is about 33.5104 using three-pattern projects to the actual voltage determination and a precision of about 1.52104 can be reached using a minimum of three patterns for the

11、determination of the single “a” parameter and about 5104 for the determination of the complete set of LPs for six diffraction patterns. Moreover, the use of three (or more) patterns allows also to overcome the ambiguity problem linked to the CBED study. The multiple-pattern approach has the drawback

12、 of reducing the spatial resolution due to the different tilt angles used for the acquisition of the diffraction patterns. However, for usual study, when only three patterns are necessary, the effect of the tilt, which can be relatively small, is not detrimental.,Determination of lattice parameters

13、from multiple CBED patterns: A statistical approachOriginal Research ArticleUltramicroscopy, Volume 110, Issue 4, March 2010, Pages 269-277G. Brunetti, E. Bouzy, J.J. Fundenberger, A. Morawiec, A. Tidu,Lattice distortions in GaN on sapphire using the CBEDHOLZ techniqueOriginal Research ArticleUltram

14、icroscopy, Volume 109, Issue 10, September 2009, Pages 1250-1255D.V. Sridhara Rao, K. McLaughlin, M.J. Kappers, C.J. Humphreys,Effect of WC or NbC addition on lattice parameter of surrounding structure in Ti(C0.7N0.3)Ni cermets investigated by TEM/CBEDOriginal Research ArticleJournal of the European Ceramic Society, Volume 30, Issue 10, August 2010, Pages 2131-2138Seongwon Kim, Jian-Min Zuo, Shinhoo Kang,Effect of sample