Determination of Mean Inner Potential and Inelastic Mean Free Path of ZnTe Using Off-Axis Electron Holography and Dynamical Effects Affecting Phase Determination

2015 ◽  
Vol 21 (6) ◽  
pp. 1406-1412 ◽  
Author(s):  
Zhaofeng Gan ◽  
Michael DiNezza ◽  
Yong-Hang Zhang ◽  
David J. Smith ◽  
Martha R. McCartney
Keyword(s):  
Free Path ◽  
Incident Beam ◽  
Mean Free Path ◽  
Bloch Wave ◽  
Electron Holography ◽  
Phase Imaging ◽  
Phase Measurements ◽  
Specimen Orientation ◽  
Convergent Beam ◽  
Inelastic Mean Free Path

AbstractThe mean inner potential (MIP) and inelastic mean free path (IMFP) of undoped ZnTe are determined using a combination of off-axis electron holography and convergent beam electron diffraction. The ZnTe MIP is measured to be 13.7±0.6 V, agreeing with previously reported simulations, and the IMFP at 200 keV is determined to be 46±2 nm for a collection angle of 0.75 mrad. Dynamical effects affecting holographic phase imaging as a function of incident beam direction for several common semiconductors are systematically studied and compared using Bloch wave simulations. These simulation results emphasize the need for careful choice of specimen orientation when carrying out quantitative electron holography studies in order to avoid erroneous phase measurements.

Determination of the Inelastic Mean-Free-Path and Mean Inner Potential for AlAs and GaAs Using Off-Axis Electron Holography and Convergent Beam Electron Diffraction

2007 ◽  
Vol 13 (5) ◽  
pp. 329-335 ◽  
Author(s):  
Suk Chung ◽  
David J. Smith ◽  
Martha R. McCartney
Keyword(s):  
Electron Diffraction ◽  
Theoretical Calculations ◽  
Mean Free Path ◽  
High Energy ◽  
Convergent Beam Electron Diffraction ◽  
Electron Holography ◽  
Beam Electron ◽  
The Mean ◽  
Convergent Beam ◽  
Inelastic Mean Free Path

The mean-free-paths for inelastic scattering of high-energy electrons (200 keV) for AlAs and GaAs have been determined based on a comparison of thicknesses as measured by electron holography and convergent-beam electron diffraction. The measured values are 77 ± 4 nm and 67 ± 4 nm for AlAs and GaAs, respectively. Using these values, the mean inner potentials of AlAs and GaAs were then determined, from a total of 15 separate experimental measurements, to be 12.1 ± 0.7 V and 14.0 ± 0.6 V, respectively. These latter measurements show good agreement with recent theoretical calculations within experimental error.

Parameterization of the mean free path for inelastic scattering of fast electrons

1987 ◽  
Vol 45 ◽  
pp. 122-123
Author(s):  
R. F. Egerton ◽  
S. C. Cheng ◽  
T. Malis
Keyword(s):  
Energy Loss ◽  
Free Path ◽  
Mean Free Path ◽  
Fast Electrons ◽  
Before And After ◽  
The Mean ◽  
Convergent Beam ◽  
Inelastic Mean Free Path ◽  
Electron Energy Loss ◽  
Beam Diffraction

The areas, Iz and It, under the zero-loss peak and under the entire energy-loss spectrum (of a sample of thickness t) are related by the formula:t/ƛ(β) = ln (It/Iz) (1)where ƛ(β) is the inelastic mean free path for all energy losses and for scattering into the collection aperture, of semiangle β. We have used Eq.(l) to experimentally determine ƛ(β) by electron energy-loss spectroscopy of specimens of known composition and thickness. In the case of crystalline samples, the local thickness t was measured by convergent-beam diffraction. In the case of evaporated thin-film specimens, the average thickness was obtained by accurately weighing the substrate before and after deposition. The energy-loss spectroscopy was carried out in CTEM mode with incident energies Eo between 20keV and 120keV, and with collection semiangles in the range 0.2 mrad to 100 mrad.

Inelastic mean free path and phase-shift determinations in NiO, using EXELFS

1993 ◽  
Vol 3 (7) ◽  
pp. 1649-1659
Author(s):  
Mohammad A. Tafreshi ◽  
Stefan Csillag ◽  
Zou Wei Yuan ◽  
Christian Bohm ◽  
Elisabeth Lefèvre ◽  
...  
Keyword(s):  
Phase Shift ◽  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path

Low-energy electron inelastic mean free path and elastic mean free path of graphene

2021 ◽  
Vol 118 (5) ◽  
pp. 053104
Author(s):  
L. H. Yang ◽  
B. Da ◽  
H. Yoshikawa ◽  
S. Tanuma ◽  
J. Hu ◽  
...  
Keyword(s):  
Free Path ◽  
Mean Free Path ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron ◽  
Inelastic Mean Free Path

The effect of elastic scattering on the effective inelastic mean free path

Vacuum ◽  
1983 ◽  
Vol 33 (10-12) ◽  
pp. 767-769 ◽  
Author(s):  
V.M. Dwyer ◽  
J.A.D. Matthew
Keyword(s):  
Elastic Scattering ◽  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path

Determination of Mean Free Path for Inelastic Scattering in Poly(2-Vinyl Pyridine) by Low-Loss Spectrum Imaging

2000 ◽  
Vol 6 (S2) ◽  
pp. 224-225
Author(s):  
A. Aitouchen ◽  
T. Chou ◽  
M. Libera ◽  
M. Misra
Keyword(s):  
Free Path ◽  
Free Fall ◽  
Mean Free Path ◽  
Specimen Thickness ◽  
Thickness Determination ◽  
Vinyl Pyridine ◽  
Integrated Intensity ◽  
Inelastic Mean Free Path ◽  
Electron Energy Loss

The common experimental method to determine the total inelastic mean free path i by electron energy-loss spectroscopy (EELS) is by the relation : t/λi= ln(It/IO) [1] where t is the specimen thickness, It, is the total integrated intensity, and Io is the intensity of the zero-loss peak. The accuracy of this measurement depends on the thickness determination. Model geometries like cubes, wedges, and spheres enable accurate thickness determination from transmission images.Spherical polymers with diameters of order 10-200nm can be made from a number of high-Tg polymers by solvent atomization. This research studied atomized spheres of poly(2-vinyl pyridine) [PVP]. A solution of 0.1% PVP in THF was nebulized. After solvent evaporation during free fall within the chamber atmosphere, solid spherical polymer particles with a range of diameters were collected on holey-carbon TEM grids at the bottom of the atomization chamber.

scholarly journals Stopping Powers and Inelastic Mean Free Path of 100 eV to 30 keV Electrons in Zirconium Silicates

2013 ◽  
Vol 38 (3) ◽  
pp. 100 ◽  
Author(s):  
D. Tahir ◽  
Suarga Suarga ◽  
Yulianti Yulianti ◽  
N.H. Sari
Keyword(s):  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path
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