Energy-filtered electron microscopy study on phase transformation of alloys
Energy-filtered electron microscopy study on phase transformation of alloys
复制标题
合金相变的能量过滤电子显微镜研究
DOI：
10.1016/s0921-5093(00)01857-8
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Y. Ikematsu
中科院分区：
文献类型：
--
作者：
D. Shindo;Y. Murakami;Y. Ikematsu
结合作者近年来的工作，综述了电子显微学，特别是能量过滤电子显微学在合金相变研究中的最新进展。在Cu72.5Pd27.5和Ti50Ni48Fe2合金的能量过滤电子衍射花样中，通过背景扣除，可以清楚地观察到分别由扩散相变和位移相变引起的弱扩散散射。在Cu72.5Pd27.5合金的短程有序状态下，通过仔细评估动态衍射对漫散射的影响，定量地评估了短程有序参数。另一方面，在Ti50Ni48Fe2合金的预马氏体状态下，通过能量过滤电子衍射和原位暗场电子显微镜，澄清了小于5 nm的微畴的形态和生长过程，具有单一的横向类型的原子位移。此外，通过对Ti50Ni48Fe2合金L2，3芯边的原位电子能量损失谱，分析了马氏体相变引起的电子结构变化。因此，它清楚地表明，先进的电子显微镜，利用电子能量损失谱是有效的，使明确的晶体和电子结构的变化与合金中的相变。
Recent progress of electron microscopy on phase transformations of alloys, especially energy-filtered electron microscopy, was reviewed mainly on the basis of the recent works by the authors. In the energy-filtered electron diffraction patterns of both Cu72.5Pd27.5and Ti50Ni48Fe2alloys, weak diffuse scattering which resulted from the diffusional and displacive phase transformations, respectively, was clearly observed by virtue of the background subtraction. In a short-range ordered state of a Cu72.5Pd27.5alloy, through the careful evaluation of the dynamical diffraction effect on the diffuse scattering, short-range order parameters were evaluated quantitatively. On the other hand, in the premartensitic state of a Ti50Ni48Fe2alloy, the morphology and growth process of microdomains less than 5 nm with a single transverse type of atomic displacement were clarified by energy-filtered electron diffraction and in situ dark-field electron microscopy. Furthermore, through in situ electron energy-loss spectroscopy on L2,3core edges of a Ti50Ni48Fe2alloy, the change in the electronic structure due to the martensitic transformation was analyzed. Thus, it is clearly demonstrated that advanced electron microscopy utilizing electron energy-loss spectroscopy is effective to make clear the change in both crystal and electronic structures associated with phase transformations in alloys.