scholarly journals Low Temperature Conductivity inn-Type Noncompensated Silicon below Insulator-Metal Transition

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
A. L. Danilyuk ◽  
A. G. Trafimenko ◽  
A. K. Fedotov ◽  
I. A. Svito ◽  
S. L. Prischepa
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Density Of States ◽  
High Accuracy ◽  
Variable Range Hopping ◽  
Temperature Conductivity ◽  
Insulator Metal Transition ◽  
Type Variable ◽  
Impurity Bands ◽  
Increasing Temperature

We investigate the transport properties ofn-type noncompensated silicon below the insulator-metal transition by measuring the electrical and magnetoresistances as a function of temperatureTfor the interval 2–300 K. Experimental data are analyzed taking into account possible simple activation and hopping mechanisms of the conductivity in the presence of two impurity bands, the upper and lower Hubbard bands (UHB and LHB, resp.). We demonstrate that the charge transport develops with decreasing temperature from the band edge activation (110–300 K) to the simple activation with much less energy associated with the activation motion in the UHB (28–90 K). Then, the Mott-type variable range hopping (VRH) with spin dependent hops occurs (5–20 K). Finally, the VRH in the presence of the hard gap (HG) between LHB and UHB (2–4 K) takes place. We propose the empiric expression for the lowTdensity of states which involves both the UHB and LHB and takes into account the crossover from the HG regime to the Mott-type VRH with increasing temperature. This allows us to fit the lowTexperimental data with high accuracy.

scholarly journals TENOXICAM PERFORMANCES FOR ALUMINIUM CORROSION INHIBITION IN 2M H2SO4: EXPERIMENTAL AND QUANTUM CHEMICAL APPROACHES

2021 ◽  
Vol 9 (07) ◽  
pp. 654-667
Author(s):  
Kalifa Mariko ◽  
◽  
Donourou Diabate ◽  
Paulin Marius Niamien ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Low Temperature ◽  
Quantum Chemical ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Molecular Descriptors ◽  
Good Reliability ◽  
Increasing Temperature ◽  
Global And Local

The inhibiting performances of Tenoxicam against aluminium corrosion in 2M H2SO4 have been tested. The results show thatinhibition efficiency increases withincrease in tenoxicam concentration,but decreases with increasing temperature. The experimental data show that the adsorption process follows the Villamil isotherm. The thermodynamic adsorption and activationfunctions were determined and analysed. The adsorption of the molecule onto the aluminium surface is an exothermic and spontaneous process. The Adejo-Ekwenchi isotherm indicatesa mixed adsorption type, but essentially physisorption at low temperature and chemisorption at high temperature. The global and local molecular descriptors confirmedthe existence of a mixed adsorption type.The QSPR studies based on two sets of energetic molecular parameters ( , ) and ( show a good reliability between inhibition efficiency and the mentioned descriptors.

Seeking the Good Fitting Procedure of PALS Polymer Spectra

2008 ◽  
Vol 607 ◽  
pp. 64-66
Author(s):  
Nicolas Laforest ◽  
Jérémie De Baerdemaeker ◽  
Corine Bas ◽  
Charles Dauwe
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Positron Annihilation ◽  
Physical Meaning ◽  
Lifetime Measurements ◽  
Positron Annihilation Lifetime ◽  
Fitting Procedure ◽  
Fitting Procedures ◽  
Blob Model

Positron annihilation lifetime measurements on polymethylmethacrylate (PMMA) at low temperature were performed. Different discrete fitting procedures have been used to analyze the experimental data. It shows that the extracted parameters depend strongly on the fitting procedure. The physical meaning of the results is discussed. The blob model seems to give the best annihilation parameters.

Anthracene fluorescence at low temperatures. I. Purified single crystals

1972 ◽  
Vol 25 (7) ◽  
pp. 1411 ◽  
Author(s):  
LE Lyons ◽  
LJ Warren
Keyword(s):  
Low Temperature ◽  
Single Crystals ◽  
Fluorescence Spectrum ◽  
Low Temperatures ◽  
Free Exciton ◽  
Deformation Bands ◽  
Exciton Emission ◽  
Polarized Emission ◽  
Impurity Bands ◽  
Phonon Structure

The low-temperature fluorescence spectrum of purified vapour-grown anthracene single crystals is presented and the free-exciton emission distinguished from a number of defect or impurity bands present even in the purest crystals. In assigning the observed bands the symmetry of the active vibrations and the origin of background fluorescence and deformation bands are discussed. The phonon structure in the region of the fluorescence origin was found to be almost completely b-polarized. Emission of electronic origin (25103 cm-1) was too weak to be observed. Polarization ratios of the principal vibronio bands at 5.6 K are given.

scholarly journals Low-temperature thermal hydrolysis of sludge prior to anaerobic digestion: principal component analysis (PCA) of experimental data

Data in Brief ◽  
2021 ◽  
pp. 107323
Author(s):  
Mohamed N.A. Meshref ◽  
Seyed Mohammad Mirsoleimani Azizi ◽  
Wafa Dastyar ◽  
Rasha Maal-Bared ◽  
Bipro Ranjan Dhar
Keyword(s):  
Experimental Data ◽  
Principal Component Analysis ◽  
Anaerobic Digestion ◽  
Low Temperature ◽  
Principal Component ◽  
Component Analysis ◽  
Thermal Hydrolysis ◽  
Hydrolysis Of

Infrared spectra of the ammonium ion in crystals. Part VIII. Spectroscopic criteria of highly-bent hydrogen bonds

1980 ◽  
Vol 58 (9) ◽  
pp. 867-874 ◽  
Author(s):  
Osvald Knop ◽  
Wolfgang J. Westerhaus ◽  
Michael Falk
Keyword(s):  
Low Temperature ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Ammonium Ion ◽  
Temperature Transition ◽  
Increasing Temperature

Available evidence suggests that (1) the stretching frequencies of highly-bent hydrogen bonds decrease with increasing temperature, regardless of whether the bonds are static or dynamic in character, to a single acceptor or to several competing acceptors; and (2) departures from symmetric trifurcation (or bifurcation) toward asymmetric situations lower the stretching frequency. In further support of these criteria isotopic probe ion spectra between 10 K and room temperature have been obtained for taurine and for trigonal (NH4)2MF6 (M = Si, Ge, Sn, Ti). Evidence of a low-temperature transition at 100(10) K in trigonal (NH4)2SnF6 is presented, and existence of the previously reported transition at 38.6 K in trigonal (NH4)2SiF6 is confirmed. Symmetry changes associated with these transitions are discussed.

Electron drift caused by rf field gradient creates many plasma phenomena: An attempt to distinguish the cause and the effect

2011 ◽  
Vol 78 (2) ◽  
pp. 165-174 ◽  
Author(s):  
C. L. XAPLANTERIS ◽  
E. D. FILIPPAKI ◽  
I. S. MISTAKIDIS ◽  
L. C. XAPLANTERIS
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Low Temperature ◽  
Mathematical Models ◽  
Field Gradient ◽  
Collision Frequency ◽  
The Other ◽  
Frequency Effect ◽  
Electron Drift ◽  
Plasma Parameters

AbstractMany experimental data along with their theoretical interpretations on the rf low-temperature cylindrical plasma have been issued until today. Our Laboratory has contributed to that research by publishing results and interpretative mathematical models. With the present paper, two issues are being examined; firstly, the estimation of electron drift caused by the rf field gradient, which is the initial reason for the plasma behaviour, and secondly, many new experimental results, especially the electron-neutral collision frequency effect on the other plasma parameters and quantities. Up till now, only the plasma steady state was taken into consideration when a theoretical elaboration was carried out, regardless of the cause and the effect. This indicates the plasma's complicated and chaotic configuration and the need to simplify the problem. In the present work, a classification about the causality of the phenomena is attempted; the rf field gradient electron drift is proved to be the initial cause.

Excess Low Temperature Specific Heat and Related Phonon Density of States in a Modulated Incommensurate Dielectric

1996 ◽  
Vol 76 (13) ◽  
pp. 2334-2337 ◽  
Author(s):  
J. Etrillard ◽  
J. C. Lasjaunias ◽  
K. Biljakovic ◽  
B. Toudic ◽  
G. Coddens
Keyword(s):  
Low Temperature ◽  
Specific Heat ◽  
Density Of States ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Low Temperature Specific Heat

Study on Low Temperature Conduction Mechanism of Al Doped ZnO/SiO2/ P-Si Heterojunction

2021 ◽  
Vol 904 ◽  
pp. 363-368
Author(s):  
Xiao Yan Zhou ◽  
Bang Sheng Yin
Keyword(s):  
Activation Energy ◽  
Impedance Spectroscopy ◽  
Low Temperature ◽  
Grain Boundaries ◽  
Ac Conductivity ◽  
Spray Pyrolysis Method ◽  
Temperature Conductivity ◽  
Calculated Activation Energy ◽  
Doped Zno ◽  
Temperature Conduction

The 3 at% Al doped ZnO thin films were deposited on p-Si substrate with a native SiO2 layer by spray pyrolysis method. Low temperature conduction behaviors were studied by analysis of impedance spectroscopy and low temperature ac conductivity. The results of impedance spectroscopy showed that the grain boundaries contributed to the resistivity of Al doped ZnO/SiO2/p-Si heterojunction. The calculated activation energy was 0.073 eV for grain boundaries. The equivalent circuit to demonstrate the electrical properties of Al doped ZnO/SiO2/p-Si heterojunction was a series connection of two parallel combination circuits of a resistor and a universal capacitor. Low temperature ac conductivity measurements indicated that the conductivity increased with temperature. Low temperature conductivity mechanism was electron conductivity, and the activation energy was 0.086 eV.

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