High Resolution Electron Microscopy 高分辨电子显微本
High Resolution Electron Microscopy 高分辨电子显微术
What are we looking at in HREM? How can we look? Why are contrast generated? Unit Amorphous Sheet Top Side 1 mm The dark spots are Si-O-Si columns that correspond with the top and side views
• What are we looking at in HREM? • How can we look? • Why are contrast generated? 2 The dark spots are Si-O-Si columns that correspond with the top and side views
L12-Ni3Al viewing along [001] B//110] 3 nm 3
L12 -Ni3Al 3
Ni-Al-Re 2nm Y 4 X.X.Yu et al.Journal of Alloys and Compounds 582 (2014)299-304
4 X.X. Yu et al. / Journal of Alloys and Compounds 582 (2014) 299–304
● 晶界 单
• 晶界
孪晶 02645A Twin SE 5um
• 孪晶 ·
·纳米金颗粒 40nm 纳米管
• 纳米金颗粒 纳米管
Imaging atom columns/lattice planes Go to a zone axis orientation Low index zone axis is preferred ·eg.[110],[001]or[111]for fcc It is because of the resolution limit of the EMs. 8
Imaging atom columns/lattice planes • Go to a zone axis orientation • Low index zone axis is preferred • eg. [110], [001] or [111] for fcc • It is because of the resolution limit of the EMs. 8
Imaging using more than one beam ●透射波 ·衍射波 (a) (b) (c) Bright field Dark field HREM Amplitude contrast 9
Imaging using more than one beam 9 Bright field Dark field HREM Amplitude contrast
衍射衬度和相位衬度 试样 28 20 物镜 物镜光阑 后焦平面 像平面 (a)散射吸收衬度 (b)相位衬度 (振幅衬度)
衍射衬度和相位衬度 • Yi
