scholarly journals Mapping the Magnetic Coupling of Self-Assembled Fe3O4 Nanocubes by Electron Holography

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 774 ◽  
Author(s):  
Lluís López-Conesa ◽  
Carlos Martínez-Boubeta ◽  
David Serantes ◽  
Sonia Estradé ◽  
Francesca Peiró
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Magnetic Induction ◽  
Theoretical Calculations ◽  
Magnetic Coupling ◽  
Magnetic Configuration ◽  
Electron Holography ◽  
Transmission Electron ◽  
Self Assembled ◽  
Good Agreement

The nanoscale magnetic configuration of self-assembled groups of magnetite 40 nm cubic nanoparticles has been investigated by means of electron holography in the transmission electron microscope (TEM). The arrangement of the cubes in the form of chains driven by the alignment of their dipoles of single nanocubes is assessed by the measured in-plane magnetic induction maps, in good agreement with theoretical calculations.

Reconstruction of electron holograms recorded in a non-FEG, non-biprism TEM

1995 ◽  
Vol 53 ◽  
pp. 618-619
Author(s):  
Z.L. Wang
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Experimental Technique ◽  
Transmission Electron Microscope ◽  
The Other ◽  
Electron Holography ◽  
Transmission Electron ◽  
Coherent Sources ◽  
Imaging Theory ◽  
Normal Specimen

An experimental technique for performing electron holography using a non-FEG, non-biprism transmission electron microscope (TEM) has been introduced by Ru et al. A double stacked specimens, one being a single crystal foil and the other the specimen, are loaded in the normal specimen position in TEM. The single crystal, which is placed onto the specimen, is responsible to produce two beams that are equivalent to two virtual coherent sources illuminating the specimen beneath, thus, permitting electron holography of the specimen. In this paper, the imaging theory of this technique is described. Procedures are introduced for digitally reconstructing the holograms.

Characterization of JEOL 3000f TEM Equipped for Electron Holography

2000 ◽  
Vol 6 (S2) ◽  
pp. 228-229
Author(s):  
M. A. Schofield ◽  
Y. Zhu
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Design Of Experiment ◽  
Electron Holography ◽  
Fringe Spacing ◽  
Interference Fringes ◽  
Transmission Electron ◽  
Careful Design

Quantitative off-axis electron holography in a transmission electron microscope (TEM) requires careful design of experiment specific to instrumental characteristics. For example, the spatial resolution desired for a particular holography experiment imposes requirements on the spacing of the interference fringes to be recorded. This fringe spacing depends upon the geometric configuration of the TEM/electron biprism system, which is experimentally fixed, but also upon the voltage applied to the biprism wire of the holography unit, which is experimentally adjustable. Hence, knowledge of the holographic interference fringe spacing as a function of applied voltage to the electron biprism is essential to the design of a specific holography experiment. Furthermore, additional instrumental parameters, such as the coherence and virtual size of the electron source, for example, affect the quality of recorded holograms through their effect on the contrast of the holographic fringes.

Aberration Correction and Electron Holography

2010 ◽  
Vol 16 (4) ◽  
pp. 434-440 ◽  
Author(s):  
Hannes Lichte ◽  
Martin Linck ◽  
Dorin Geiger ◽  
Michael Lehmann
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fine Tuning ◽  
Electron Holography ◽  
Aberration Correction ◽  
Quantitative Interpretation ◽  
A Posteriori ◽  
Atomic Structures ◽  
Basic Reason ◽  
Transmission Electron

AbstractElectron holography has been shown to allow a posteriori aberration correction. Therefore, an aberration corrector in the transmission electron microscope does not seem to be needed with electron holography to achieve atomic lateral resolution. However, to reach a signal resolution sufficient for detecting single light atoms and very small interatomic fields, the aberration corrector has turned out to be very helpful. The basic reason is the optimized use of the limited number of “coherent” electrons that are provided by the electron source, as described by the brightness. Finally, quantitative interpretation of atomic structures benefits from the holographic facilities of fine-tuning of the aberration coefficients a posteriori and from evaluating both amplitude and phase.

Low Voltage Point Projection Microscopy and Time of Flight Stm - Two New Microscopies

1994 ◽  
Vol 332 ◽  
Author(s):  
J.C.H. Spence ◽  
W. Qian ◽  
W. Lo ◽  
S. Mo ◽  
U. Knipping ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Low Voltage ◽  
Time Of Flight ◽  
Atomic Clusters ◽  
Electron Holography ◽  
Transmission Electron ◽  
Point Projection ◽  
Projection Field

ABSTRACTThe design of a low voltage point-projection field-emission transmission electron microscope is described and images showing 0.7nm resolution at 100 volts are given. A scheme for low voltage reflection electron holography from bulk samples in UHV is outlined. A new STM is described which allows atomic clusters to be transferred onto the tip, then introduced into a time-of-flight analyser for species identification.

Development of a 1MV-Field-Emission Electron Microscope I. Instrument

2000 ◽  
Vol 6 (S2) ◽  
pp. 1138-1139
Author(s):  
I. Matsui ◽  
T. Katsuta ◽  
T. Kawasaki ◽  
S. Hayashi ◽  
T. Furutsu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Resolution Imaging ◽  
Electron Microscopes

We have developed 100-kV, 200-kV, and 350-kV cold-field-emission transmission electron microscopes (FE-TEMs) successively up to this time. Using these instruments, we have been studying the magnetic structure of materials, high-resolution imaging by electron holography, and dynamic observation of the vortex in superconductors by Lorentz microscopy. To make more progress in our research, we need a better electron beam in terms of coherency, beam brightness, and penetration. Here, we report a new lMV-cold-field-emission transmission electron microscope we have developed. Historically, the pioneering projects on a lMV-field-emission scanning transmission electron microscope (FE-STEM) (Zeitler and Crewe, 1974) and a 1.6MV FE-STEM (Jouffrey et al., 1984) have been reported. In 1988, Maruse and Shimoyama obtained a lMV-field-emission beam using their 1.25MV-STEM connected to a field-emission gun. Since then, continuous improvements in beam brightness has been made.The target specifications of our 1 MV-cold-field-emission TEM (H-1000FT) are as follows: Acceleration voltage: 1MV, high-voltage stability :

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