Electron-phonon enhancement of the thermal electron mass in impure systems

1974 ◽  
Vol 18 (2) ◽  
pp. 161-164 ◽  
Author(s):  
G�ran Grimvall
Keyword(s):  
Electron Mass ◽  
Thermal Electron ◽  
Impure Systems

scholarly journals Parameters of Charge Carrier Traps in ZnSe

2019 ◽  
Vol 64 (4) ◽  
pp. 300
Author(s):  
V. Ya. Degoda ◽  
M. Alizadeh
Keyword(s):  
Cross Sections ◽  
Thermionic Emission ◽  
Effective Density ◽  
Electron Mass ◽  
Thermal Electron ◽  
Effective Electron ◽  
Conductivity Type ◽  
Thermal Emf ◽  
Temperature Dependences ◽  
Carrier Traps

Taking zinc selenide (ZnSe) crystals as an example, a procedure of determination of the main parameters of traps is proposed. At first, the conductivity type (electron or hole one) in a crystal of phosphor at its excitation is determined with the help of photoelectric studies or studies of the thermionic emission or thermal or photo-thermal emf. Then the energy of the thermal electron delocalization is determined, e.g., by using the method of thermally stimulated luminescence with sequential fractional heating. As a result, the frequency factors of corresponding traps are found as well. Knowing the effective electron mass, it is easy to calculate the effective density of electron states in the conduction band. Finally, the cross sections of the free-electron localization and their temperature dependences can be determined for all traps from a simple equation.

Recent developments in low-voltage SEM of polymers

1993 ◽  
Vol 51 ◽  
pp. 866-867
Author(s):  
S.J. Krause ◽  
W.W. Adams
Keyword(s):  
Low Voltage ◽  
Chromatic Aberration ◽  
Thermal Electron ◽  
Analytical Technique ◽  
Recent Developments ◽  
Beam Currents ◽  
New Generation ◽  
First Time ◽  
Voltage Scanning ◽  
Beam Damage

Over the past decade low voltage scanning electron microscopy (LVSEM) of polymers has evolved from an interesting curiosity to a powerful analytical technique. This development has been driven by improved instrumentation and in particular, reliable field emission gun (FEG) SEMs. The usefulness of LVSEM has also grown because of an improved theoretical and experimental understanding of sample-beam interactions and by advances in sample preparation and operating techniques. This paper will review progress in polymer LVSEM and present recent results and developments in the field.In the early 1980s a new generation of SEMs produced beam currents that were sufficient to allow imaging at low voltages from 5keV to 0.5 keV. Thus, for the first time, it became possible to routinely image uncoated polymers at voltages below their negative charging threshold, the "second crossover", E2 (Fig. 1). LVSEM also improved contrast and reduced beam damage in sputter metal coated polymers. Unfortunately, resolution was limited to a few tenths of a micron due to the low brightness and chromatic aberration of thermal electron emission sources.

Large Electron Mass Anisotropy in Anatase Ti1-xNbxO2 Transparent Conductor

2008 ◽  
Author(s):  
Yasushi Hirose ◽  
Naoomi Yamada ◽  
Shoichiro Nakao ◽  
Taro Hitosugi ◽  
Toshihiro Shimada ◽  
...  
Keyword(s):  
Electron Mass ◽  
Transparent Conductor

scholarly journals New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 344
Author(s):  
T. D. Le
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Space Time ◽  
Fine Structure Constant ◽  
Electron Mass ◽  
Mass Ratio ◽  
Quasar Spectra ◽  
Time Variations ◽  
Using Data ◽  
The Universe

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.

scholarly journals Surface and volume photoeffect from metal nanoparticles with electron mass discontinuity

2021 ◽  
Vol 103 (23) ◽  
Author(s):  
Igor E. Protsenko ◽  
Alexander V. Uskov ◽  
Nikolay V. Nikonorov
Keyword(s):  
Metal Nanoparticles ◽  
Electron Mass

scholarly journals Equilibration of the chiral asymmetry due to finite electron mass in electron-positron plasma

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
A. Boyarsky ◽  
V. Cheianov ◽  
O. Ruchayskiy ◽  
O. Sobol
Keyword(s):  
Electron Mass ◽  
Chiral Asymmetry ◽  
Electron Positron

scholarly journals SECOND-ORDER CORRECTIONS TO QED COUPLING AT LOW TEMPERATURE

2008 ◽  
Vol 23 (29) ◽  
pp. 4709-4719 ◽  
Author(s):  
SAMINA S. MASOOD ◽  
MAHNAZ HASEEB
Keyword(s):  
Low Temperatures ◽  
Vacuum Polarization ◽  
Second Order ◽  
Electromagnetic Properties ◽  
Electron Mass ◽  
Polarization Tensor ◽  
Coupling Constant ◽  
Electric Permittivity ◽  
Thermal Medium ◽  
Vacuum Polarization Tensor

We calculate the second-order corrections to vacuum polarization tensor of photons at low temperatures, i.e. T ≪ 1010 K (T ≪ me). The thermal contributions to the QED coupling constant are evaluated at temperatures below the electron mass that is T < me. Renormalization of QED at these temperatures has explicitly been checked. The electromagnetic properties of such a thermal medium are modified. Parameters like electric permittivity and magnetic permeability of such a medium are no more constant and become functions of temperature.

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