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Volumn 10, Issue 8, 2010, Pages 3190-3198

Nonchaotic nonlinear motion visualized in complex nanostructures by stereographic 4D electron microscopy

Author keywords

4D microscopy; nanomechanical systems; shape memory materials; ultrafast electron imaging

Indexed keywords

BINARY ALLOYS; ELECTRON MICROSCOPES; ELECTRON MICROSCOPY; NANOSTRUCTURES; SHAPE MEMORY EFFECT; TITANIUM ALLOYS;

EID: 77955564702     PISSN: 15306984     EISSN: 15306992     Source Type: Journal    
DOI: 10.1021/nl102141t     Document Type: Article
Times cited : (17)

References (31)
  • 13
    • 77950802384 scopus 로고    scopus 로고
    • references therein
    • Zewail, A. H. Science 2010, 328, 187-193 and references therein
    • (2010) Science , vol.328 , pp. 187-193
    • Zewail, A.H.1
  • 23
    • 77955583339 scopus 로고    scopus 로고
    • note
    • Before use in construction of 4D trajectories, the 2D coordinates for α = -30°, 0°, and 40° were checked to confirm the geometric requirement of invariance with α of the projections of a point on the tilt axis; orientation was determined by a static TEM tilt-series analysis. The condition was satisfied by the points in negative-time images of the UEM series, as expected, but evidence of a change in amplitude (50% larger for α = 0°, and 80% larger for α = -30°, than for α = 40°) of the dynamic response to constant excitation fluence with tilt angle was unambiguous. This increase in amplitude with decrease in tilt angle is understandable because the angle of illumination of the specimen is fixed in the microscope (almost collinear with the electron beam). Thus the exposed cross section for absorption of the light and the angle of incidence on the surfaces of the structure as well as the resulting distribution of heating within the specimen vary greatly as the tilt angle changes. To adjust for this difference and use the stereo information provided by the recorded time series at α = 0° and 40°, both 2D dimensions of the dynamics in the α = 40° data were scaled up by a factor of 1.5, under the assumption of an isotropic amplitude response to the change in tilt. Because of the aforementioned small variations in the frequency response, an adjustment of the α = 0° time scale (by 0.978) was also necessary to accurately match the temporal behavior of the projected components of the dynamics on the tilt axis. A small, monotonically varying baseline difference in the data at the two tilts was not eliminated, but the presence or absence of this slow variation should have little effect on the analysis of the oscillatory motion that follows. The α = -30° data were not used in the 4D reconstruction because, with the specimen subjected to four times as many thermal cycles in the interval between data collection at α = 40° and -30° as in the interval between α = 0° and α = 40°, and with maximum oscillation amplitude at -30°, the recorded dynamic behavior at -30° showed evident differences from α = 0° and 40° in interference effects among the frequency components.
  • 31
    • 0002992492 scopus 로고
    • references therein
    • Zewail, A. H. Phys. Today 1980, 33, 2-8 and references therein
    • (1980) Phys. Today , vol.33 , pp. 2-8
    • Zewail, A.H.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.