Preliminary Experimental Results from the Multi-Energy Electron Gun

2022 ◽  
Author(s):  
Miles Bengtson
Keyword(s):  
Experimental Results ◽  
Energy Electron ◽  
Electron Gun

Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

1974 ◽  
Vol 32 ◽  
pp. 390-391
Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya
Keyword(s):  
Field Emission ◽  
Phase Contrast ◽  
Image Formation ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electron Gun ◽  
Scanning Microscopy ◽  
Emission Electron ◽  
Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

Spin Polarized Low Energy Electron Microscopy of Surface Magnetic Structure

1991 ◽  
Vol 232 ◽  
Author(s):  
M. S. Altman ◽  
H. Pinkvos ◽  
J. Hurst ◽  
H. Poppa ◽  
G. Marx ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Structure ◽  
Electron Beams ◽  
Low Energy ◽  
Energy Electron ◽  
Electron Gun ◽  
Image Subtraction ◽  
Topological Features ◽  
Spin Polarized ◽  
Low Energy Electron

ABSTRACTSpin polarized low energy electron microscopy (SPLEEM) has been developed for the high resolution imaging of surface magnetic structure. The existing LEEM ha.s been modified by the incorporation of a. GaAs-type spin polarized electron gun. Large image contrast arises due to the spin-dependent exchange scattering, whifle the st.in-orbit contribution vanishes uniquely for the normal incidence/exit geometry used here. Pixel by pixel image subtraction for incident electron beams of opposite polarization yields precisely the spatially resolved Bragg reflection asymmetry observed in spin polarized low energy electron diffraction. The shallow electron penetration depth arising from the strong coulombic interaction is advantageous for separating surface behavior from the normally overwhelning bulk. Therefore, the use of transversally polarizedI electron beams allows the determination of in-plane surface magnetization directions. Fnrthermore, the parallel illumination and detection of SPLEEM makes it possible to image quickly with a. resolution better than 500 Å in the present configuration. A useful and direct. comparison between surface magnetic, structural, and topological features is made possible by the augmentation of the unique imaging capabilities of conventional LEEM with the magnetic sensitivity of SPLEEM. In this manner, the magnetic domain structure of a Co (0001) surface and in-situ grown Co filmns on Mo(110) have been determined.

Characterization of Surface Defect Structure by Low Energy Electron Diffraction

1984 ◽  
Vol 41 ◽  
Author(s):  
J. F. Wendelken ◽  
G. -C. Wang ◽  
J. M. Pimbley ◽  
T. -M. Lu
Keyword(s):  
Electron Beam ◽  
Electron Diffraction ◽  
Surface Defect ◽  
Low Energy ◽  
Experimental Results ◽  
Energy Electron ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron

AbstractLow energy electron diffraction is a surface sensitive tool which is most widely used for the determination of surface symmetries and equilibrium atomic positions. Experimental and theoretical advances made in the past five years make it possible now to use LEED also for the characterization of a wide variety of surface defect structures. In this paper a variety of experimental results involving analysis of diffracted electron beam shapes as a function of primary electron beam energy, adsorbate coverage, crystal tem-perature and ordering time are presented. These experimental results coupled with kinematic theory, allow the determination of step density, size and shape of reconstruction domains and overlayer islands, island size distribution in an overlayer during growth, and the mode of growth.

Real Time Magnetic Imaging by Spin-Polarized Low Energy Electron Microscopy with Highly Spin-Polarized and High Brightness Electron Gun

2010 ◽  
Vol 3 (2) ◽  
pp. 026601 ◽  
Author(s):  
Masahiko Suzuki ◽  
Michihiro Hashimoto ◽  
Tsuneo Yasue ◽  
Takanori Koshikawa ◽  
Yasuhide Nakagawa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Real Time ◽  
Low Energy ◽  
Energy Electron ◽  
Electron Gun ◽  
High Brightness ◽  
Magnetic Imaging ◽  
Spin Polarized ◽  
Low Energy Electron
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