Specimen chamber geometry--a possible source of error in quantitative x-ray microanalysis in STEM.
Specimen chamber geometry--a possible source of error in quantitative x-ray microanalysis in STEM.
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样本室几何形状——STEM 定量 X 射线微量分析中可能的误差源。
DOI：
10.1093/oxfordjournals.jmicro.a050327
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
H. Fromme
中科院分区：
文献类型：
--
作者：
M. Grote;H. Fromme
为了定量分析STEM中的软生物样品，我们尝试使用有机元素标准(Spur，11 Grote et a/.！‘8)建立校准曲线。在这些测量中，我们发现样品栅条相对于电子探针的位置是重要的，并且样品支架相对于电子探针和Si(Li)探测器的固定布置的位置的改变对测量有很大的影响。我们试图通过对商业标本保持器进行技术改造和建立修正因子来消除这些几何影响。材料和方法。使用日立H500透射电子显微镜，该显微镜具有侧入向心测角台，并配备高分辨率扫描附件H5010。Si(Li)探测器被放置在靠近入射光束的位置，起飞角度为68，并且位于样品上方约30 mm的距离处，该样品只能围绕其常心轴倾斜，而不能朝向探测器。对于EDX，我们同时使用了正常的标本保持器和标本保持器。使用PGT 1000Xcel微量分析系统(普林斯顿伽玛技术公司，美国普林斯顿)进行X射线微量分析。通过有机元素标准的切片，尽可能大，约1 mm厚，放置在椭圆形涂层铜网或一个孔栅(直径1 mm)上，并在以下分析条件下进行检查：放大倍数X 10,000；光斑尺寸小于100 nm(通过污染线测量)；束流，25^A；加速电压，75千伏。
For quantitative X-ray microanalysis of soft biological specimens in STEM we tried to establish calibration curves using organic element standards (Spurr, 11 Grote et a/.!'8)). During these measurements we found that the position of the bars of a specimen grid with regard to the electron probe was important and that the measurements were strongly influenced by shifting the position of the specimen holder with regard to the fixed arrangement of the electron probe and the Si (Li)-detector. We tried to eliminate these geometrical influences by technical modification of the commercial specimen holder and by the establishment of correction factors. Materials and methods. A Hitachi H 500 transmission electron microscope with a side entry eucentric goniometer stage and equipped with the high resolution scanning attachment H 5010 was used. The Si (Li)-detector is positioned close to the incident beam at a take-off angle of 68 and at a distance of approximately 30 mm above the specimen which can be tilted only around its eucentric axis, not towards the detector. We used both the normal specimen holder and the specimen holder for EDX. X-ray microanalysis was carried out using a PGT 1000 XCEL microanalysis system (Princeton Gamma Tech, Princeton, USA). Sections through organic element standards which were as large as possible and about 1 fim thick were placed upon pioloform coated copper mesh grids or one hole grids (diameter 1 mm) and examined under the following analysing conditions: magnification, X 10,000; spot size, less than 100 nm (measured by a contamination line); beam current, 25^ A; accelerating voltage, 75 kV.