[交流] 【求助】请教 Al-Ag合金 TEM 图片 衍射斑点 的问题，非常感谢！ （急）

附图1为 Al-Ag合金 TEM 图片:    图中，黑色棒 为  γ相（Ag溶质富积区）；白色带 区域为 Ag-depleted regions （贫Ag溶质的消耗区） 其他区域为 Guinier-Preston区（GPZ）。 附图1说明： BF TEM image of an edge-on g plate in a sample aged at 400 ℃ for 120 s and 160 ℃ for 48 h, with a matrix containing GP zones 已知：Al 和Ag 都是   面心立方(fcc)结构， Al-Ag合金在时效时的析出相 为 密排六方（hcp）结构。 注解： The precipitates are hexagonal-shaped within the (0001)//(111) habit plane, with edges parallel to the close-packed [11-20]//[1-10] directions. Thus, when the precipitates are oriented edge-on in a [11-20]//[1-10] zone axis, their edges are parallel to the electron beam and the exact length of the plates (facet-to-facet) can be measured without any effects of geometry or truncation in the foil. 问题：   附图1中左上角的衍射斑点（即附图2）起到了什么作用？是哪个相的斑点？   附图1 附图2 实验说明 [ Last edited by 小兰花 on 2010-8-30 at 13:50 ]

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