Ultrafast electron microscopy in material science<xref rid="cpb_27_7_070703fn1" ref-type="fn">*</xref><fn id="cpb_27_7_070703fn1"> <label>*</label><p>Project supported by the National Basic Research Program of China (Grant No. 2015CB921300), the National Key Research and Development Program of China (Grant Nos. 2016YFA0300300, 2017YFA0504703, and 2017YFA0302900), the National Natural Science Foundation of China (Grant Nos. 11604372, 11474323, and 11774391), the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB07020000), and the Scientific Instrument Developing Project of the Chinese Academy of Sciences (Grant No. ZDKYYQ20170002). Z. A. L acknowledges the financial support of the Hundred Talent Program B from CAS.</p> </fn>

Ultrafast electron microscopy in material science* *

Project supported by the National Basic Research Program of China (Grant No. 2015CB921300), the National Key Research and Development Program of China (Grant Nos. 2016YFA0300300, 2017YFA0504703, and 2017YFA0302900), the National Natural Science Foundation of China (Grant Nos. 11604372, 11474323, and 11774391), the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB07020000), and the Scientific Instrument Developing Project of the Chinese Academy of Sciences (Grant No. ZDKYYQ20170002). Z. A. L acknowledges the financial support of the Hundred Talent Program B from CAS.

Yang Huaixin^{1, 2}, Sun Shuaishuai¹, Zhang Ming^{1, 2}, Li Zhongwen^{1, 2}, Li Zian¹, Xu Peng¹, Tian Huanfang¹, Li Jianqi^{1, 2, 3, †}

(color online) Picosecond Fresnel imaging of domain-wall dynamics. (a) Sum of ten separate pulsed-photoelectron Fresnel images obtained before time zero. The black and red rectangles indicate the regions in which the degree of electron coherence was monitored as a function of time. (b) Sum of six separate pulsed photoelectron Fresnel images obtained between 470 and 480 ps (2-ps steps). The same regions indicated in (a) are highlighted. (c) Degree of electron coherence of the domain wall as a function of time. The data range from −18 to 482 ps and present the least-squares fit (red curve) with a single exponential decay having a time constant of 24 ps. (d) Magnified view of the early dynamics data and least-squares fit for the range of −18 to 68 ps. Reprinted from Ref. [58] with permission.