Influence of wave perturbations of ionospheric electron concentration on shortwave propagation

1975 ◽  
Vol 18 (8) ◽  
pp. 905-906
Author(s):  
V. I. Sazhin ◽  
M. V. Tinin
Keyword(s):  
Electron Concentration ◽  
Shortwave Propagation

A New Condition of Formation and Stablity of All Crystalline Systems in a Good Agreement with Experimental Data

2015 ◽  
Vol 11 (3) ◽  
pp. 3224-3228
Author(s):  
Tarek El-Ashram
Keyword(s):  
Experimental Data ◽  
Brillouin Zone ◽  
Electron Concentration ◽  
Free Electron ◽  
Lattice Point ◽  
Valence Electron ◽  
Fermi Gas ◽  
Valence Electron Concentration ◽  
Fermi Sphere ◽  
Good Agreement

In this paper we derived a new condition of formation and stability of all crystalline systems and we checked its validity andit is found to be in a good agreement with experimental data. This condition is derived directly from the quantum conditionson the free electron Fermi gas inside the crystal. The new condition relates both the volume of Fermi sphere VF andvolume of Brillouin zone VB by the valence electron concentration VEC as ;𝑽𝑭𝑽𝑩= 𝒏𝑽𝑬𝑪𝟐for all crystalline systems (wheren is the number of atoms per lattice point).

scholarly journals Analysis of Flexural Vibrations of a Piezoelectric Semiconductor Nanoplate Driven by a Time-Harmonic Force

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3926
Author(s):  
Mengen Li ◽  
Qiaoyun Zhang ◽  
Bingbing Wang ◽  
Minghao Zhao
Keyword(s):  
Electron Concentration ◽  
Smart Devices ◽  
Harmonic Force ◽  
Plate Structures ◽  
Piezoelectric Semiconductor ◽  
Initial Electron ◽  
Time Harmonic ◽  
Semiconductor Plate ◽  
Flexural Vibrations ◽  
Piezoelectric Semiconductors

The performance of devices fabricated from piezoelectric semiconductors, such as sensors and actuators in microelectromechanical systems, is superior; furthermore, plate structures are the core components of these smart devices. It is thus important to analyze the electromechanical coupling properties of piezoelectric semiconductor nanoplates. We established a nanoplate model for the piezoelectric semiconductor plate structure by extending the first-order shear deformation theory. The flexural vibrations of nanoplates subjected to a transversely time-harmonic force were investigated. The vibrational modes and natural frequencies were obtained by using the matrix eigenvalue solver in COMSOL Multiphysics 5.3a, and the convergence analysis was carried out to guarantee accurate results. In numerical cases, the tuning effect of the initial electron concentration on mechanics and electric properties is deeply discussed. The numerical results show that the initial electron concentration greatly affects the natural frequency and electromechanical fields of piezoelectric semiconductors, and a high initial electron concentration can reduce the electromechanical fields and the stiffness of piezoelectric semiconductors due to the electron screening effect. We analyzed the flexural vibration of typical piezoelectric semiconductor plate structures, which provide theoretical guidance for the development of new piezotronic devices.

scholarly journals Zum paramagnetischen Verhalten von Palladium/Silber/Eisen- Legierungen/ On the Paramagnetic Behaviour of Palladium-Silver-Iron Alloys

1975 ◽  
Vol 30 (5) ◽  
pp. 645-655
Author(s):  
Peter Brill
Keyword(s):  
Electron Concentration ◽  
Magnetic Moments ◽  
Alloy Series ◽  
Band Filling ◽  
Paramagnetic Behaviour ◽  
Field Coefficient ◽  
Saturation Moment ◽  
Molecular Field Coefficient ◽  
The Moment ◽  
Curie Temperatures

Abstract The paramagnetic susceptibility of four PdAgFe alloy series containing 1, 3, 5 and 7 at. % Fe have been measured between 20° and 150 °C. On the basis of a band filling model the local moment contribution to the susceptibility has been evaluated according to a Curie -Weiss law. Assuming that the iron atoms donate 3 electrons and the silver atoms 1 electron to the Pd 4d band, the effective magnetic moments and the paramagnetic Curie temperatures of all the alloys can be represented by a single curve against the electron concentration. The effective magnetic moment is consistent with an Fe moment of 5.92 μB localized on the iron sites and a Pd moment varying with electron concentration and temperature. The same turns out to be true for the ferromagnetic region where the saturation moment, obtained on PdFe alloys and a PdAgFe alloy by different authors, is considered to arise from a localized Fe moment of 5 μB and a concentration dependent Pd moment. The molecular field coefficient for the interaction between the Fe moments and the Pd 4d electrons is found to be 850 mol/cm3 at 385 K and 1200 mol/cm3 at 0 K. Finally, the iron moment suggested in this work is contrasted with the moment derived from neutron diffraction measurements.

Laser interferometry in the determination of electron concentration in plasma jets

1967 ◽  
Vol 7 (2) ◽  
pp. 143-144 ◽  
Author(s):  
A. A. Ovsyannikov ◽  
L. S. Polak ◽  
R. E. Rovinskii ◽  
A. G. Rozanov ◽  
N. N. Shvindt
Keyword(s):  
Electron Concentration ◽  
Laser Interferometry ◽  
Plasma Jets
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