Hirotsu Y, Ohkubo T, Matsushita M
Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan.
Microsc Res Tech. 1998 Feb 15;40(4):284-312. doi: 10.1002/(SICI)1097-0029(19980215)40:4<284::AID-JEMT5>3.0.CO;2-S.
Structures with atomic medium range order (MRO) extending as small as approximately 2 nm in amorphous alloys can be observed under suitable defocus conditions as clear lattice fringe images by means of axial-beam high-resolution electron microscopy (HREM). In this article, our studies of local structure observation in some metal-metalloid amorphous alloys with the "selected-defocus method" are introduced. Also introduced are an HREM image simulation study of amorphous alloy structures and a nano-probe (1-1.5 nm) electron diffraction analysis of MRO structure. A multislice image simulation study for suitable structure models (1) with a random atomic distribution, (2) with MRO regions having different sizes, distributions, and specimen thicknesses, is a necessary step to verify the MRO observation in amorphous alloys. It was demonstrated that not only HREM information but also nano-diffraction information are necessary in order to understand local structures of amorphous alloys.
在合适的散焦条件下，通过轴向束高分辨率电子显微镜（HREM），可以观察到非晶合金中原子中程有序（MRO）结构，其延伸范围小至约2纳米，呈现为清晰的晶格条纹图像。本文介绍了我们用“选择散焦法”对一些金属 - 类金属非晶合金进行局部结构观察的研究。还介绍了非晶合金结构的HREM图像模拟研究以及MRO结构的纳米探针（1 - 1.5纳米）电子衍射分析。对合适的结构模型（1）具有随机原子分布、（2）具有不同尺寸、分布和样品厚度的MRO区域进行多切片图像模拟研究，是验证非晶合金中MRO观察结果的必要步骤。结果表明，为了理解非晶合金的局部结构，不仅需要HREM信息，还需要纳米衍射信息。
