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X射线衍射线形与晶体材料的微观结构密切相关.在晶粒尺寸衍射线形和微应变衍射线形可由Voigt函数近似描述的前提下,本文较详细地论述了由X射线衍射线形分析获取晶粒尺寸和位错等微观结构信息的方法.采用这种方法,对乙二醇还原法制备的Pt/C催化剂进行了X射线衍射线形分析.样品晶粒尺寸分布的对数正态均值为0.95 nm,对数正态方差为0.37.X射线衍射线形分析所得晶粒尺寸分布与透射电镜的测试结果符合较好.对样品的衍射线形积分宽度进行细致的比较,发现存在各向异性展宽现象.如果衍射线的各向异性展宽主要是由伯格斯矢量为1/2〈110〉的位错引起,可进一步计算位错密度值.结果表明,位错组态无论是螺型位错还是刃型位错,位错密度值的量级均约为1015/m2.
The X-ray diffraction pattern is closely related to the microstructure of the crystalline material.When the grain size diffraction lines and the microdisplacement diffraction lines can be approximated by the Voigt function, the article discusses in more detail the relationship between the grain size Dislocation and other microstructure information method.With this method, ethylene glycol reduction prepared Pt / C catalyst by X-ray diffraction linear analysis sample grain size distribution of the logarithmic normal average 0.95 nm, for The normalized variance is 0.37.The grain size distribution of X-ray diffraction analysis is in good agreement with that of TEM.The detailed comparison of the diffraction integral width of the sample shows that there is an anisotropic broadening phenomenon.If the diffraction line The anisotropy broadening is mainly caused by the dislocations with the Burgers vector of 1/2 <110>, and the dislocation density can be further calculated.The results show that the dislocation configuration, whether it is screw dislocation or edge dislocation , The magnitude of dislocation density is about 1015 / m2.