scholarly journals Transport Phenomena In Single Crystals Tl1−XIn1−XGeXSe2 (x=0.1, 0.2)

2015 ◽  
Vol 60 (3) ◽  
pp. 2025-2028
Author(s):  
O.V. Zamurueva ◽  
G.L. Myronchuk ◽  
K. Oźga ◽  
M. Szota ◽  
A.M. El-Naggar ◽  
...  
Keyword(s):  
Activation Energy ◽  
Fermi Level ◽  
Single Crystals ◽  
Average Distance ◽  
Transport Phenomena ◽  
Localized States ◽  
Temperature Range ◽  
Temperature Dependences ◽  
Different Temperatures ◽  
Conductivity Band

Abstract Temperature dependences of electroconductivity for single crystals Tl1−xIn1−xGexSe2 were analyzed. It was established an occurrence of thermoactivated states within the temperature range 100-300 K. The conductivity is formed by delocalized carriers within the conductivity band and the jumping conductivity over the localized states which are situated in the narrow localized states near the Fermi level. Following the performed data the activation energy was evaluated with accuracy up to 0.02 eV. The density of the localized states as well as the distribution of the energy over the mentioned states was evaluated. Additionally the average distance between the localized states is evaluated at different temperatures.

CREEP ACTIVATION ENERGY OF FLOW PROCESS IN Sn0.2Bi1.8Te3 SINGLE CRYSTALS

2004 ◽  
Vol 11 (04n05) ◽  
pp. 443-446
Author(s):  
P. H. SONI ◽  
C. F. DESAI ◽  
S. R. BHAVSAR
Keyword(s):  
Activation Energy ◽  
Time Dependence ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Vickers Microhardness ◽  
Indentation Creep ◽  
Flow Process ◽  
Creep Activation Energy ◽  
Temperature Range ◽  
Different Temperatures

Temperature dependence of the Vickers microhardness of Sn 0.2 Bi 1.8 Te 3 single crystals has been studied. Loading time dependence of microhardness at different temperatures has been used for creep study in the temperature range 303 K–373 K. The activation energy for indentation creep of the crystals has been evaluated.

Interface Controlled Diffusional Creep of Cu + 2.8 at.% Co Solid Solution

2012 ◽  
Vol 322 ◽  
pp. 33-39 ◽  
Author(s):  
Sergei Zhevnenko ◽  
Eugene Gershman
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Surface Tension ◽  
High Temperature ◽  
Creep Behavior ◽  
Pure Copper ◽  
Diffusional Creep ◽  
High Temperature Creep ◽  
Temperature Range ◽  
Different Temperatures

High-temperature creep experiments were performed on a Cu-2.8 ат.% Co solid solution. Cylindrical foils of 18 micrometers thickness were used for this purpose. Creep tests were performed in a hydrogen atmosphere in the temperature range of about from 1233 K to 1343 K and at stresses lower than 0.25 MPa. For comparison, a foil of pure copper and Cu-20 at.% Ni solid solution were investigated on high temperature creep. Measurements on the Cu foil showed classical diffusional creep behavior. The activation energy of creep was defined and turned out to be equal 203 kJ/mol, which is close to the activation energy of bulk self-diffusion of copper. There was a significant increase in activation energy for the Cu-20 at.% Ni solid solution. Its activation energy was about 273 kJ/mol. The creep behavior of Cu-Co solid solution was more complicated. There were two stages of diffusional creep at different temperatures. The extremely large activation energy (about 480 kJ/mol) was determined at relatively low temperature and a small activation energy (about 105 kJ/mol) was found at high temperatures. The creep rate of Cu-Co solid solution was lower than that of pure copper at all temperatures. In addition, the free surface tension of Cu-2.8 ат.% Co was measured at different temperatures from 1242 K to 1352 K. The surface tension increases in this temperature range from 1.6 N/m to 1.75 N/m. There were no features on the temperature dependence of the surface tension.

scholarly journals INVESTIGATION OF ELECTRICAL CONDUCTION IN VANADATE BASED GLASSES

2013 ◽  
Vol 22 ◽  
pp. 255-260 ◽  
Author(s):  
R. V. BARDE ◽  
S. A. WAGHULEY
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Conduction ◽  
Arrhenius Equation ◽  
Localized States ◽  
Melt Quenching ◽  
Temperature Range ◽  
Dc Electrical Conductivity ◽  
Glassy Systems

The binary glassy systems 60V2O5-(40-x)P2O5 –xB2O3 were prepared by melt quenching technique. The mole of B2O3 was varies from 5 to 20 mol % with constant mol % of V2O5 during preparation of glass samples. The dc electrical conductivity of samples was measured in temperature range 303-473 K and found to be higher for sample 60 V2O5-20P2O5 –20B2O3 . Using the Arrhenius equation of conductivity, the activation energy of conduction is estimated. The conduction in these glasses is takes place by phonon-assisted hopping between the localized states.

scholarly journals Composition variation and electron irradiation effects on the fluctuation conductivity in Y1–zPrzBa2Cu3O7−δ single crystals

2020 ◽  
Vol 31 (21) ◽  
pp. 19429-19436
Author(s):  
A. Chroneos ◽  
D. D. Kolesnikov ◽  
I. A. Taranova ◽  
A. V. Matsepulin ◽  
R. V. Vovk
Keyword(s):  
Single Crystals ◽  
Oxygen Deficiency ◽  
High Energy ◽  
Superconducting Transition ◽  
Crossover Point ◽  
Fluctuation Conductivity ◽  
High Energy Electrons ◽  
Composition Variation ◽  
Temperature Dependences ◽  
Different Temperatures

AbstractA comparative analysis of the changes in the fluctuation conductivity and characteristics of the superconducting state of YBa2Cu3O7–δ single crystals caused by various types of defects is carried out. These defects appeared due to irradiation with high-energy electrons (radiation doses from 1.4 to 8.8 1018 cm–2), changes in oxygen deficiency (0.08 ≤ δ ≤ 0.23) due to annealing at different temperatures, or doping with praseodymium (Y1–zPrzBa2Cu3O7−δ, 0 ≤ z ≤ 0.5 at optimal oxygen concentration). It is shown that the introduction of such defects leads to a significant expansion of the temperature range of the existence of excess conductivity, and upon doping with praseodymium, it also leads to the appearance of a thermally activated deflection on the temperature dependence of the electrical resistance. The effect of such defects on the superconducting transition temperature, Tc, and the coherence length along the c axis, ξc(0), is studied. In particular, ξc(0) more than quadruples (at z = 0.43), while the 2D-3D crossover point shifts towards higher temperatures. Possible reasons for the suppression of superconductivity in YBa2Cu3O7–δ upon irradiation with fast electrons and the qualitatively different temperature dependences of its resistivity in the basal plane, ρab (T), are discussed.

scholarly journals Study on technology characteristics materials based on polysulfone

2016 ◽  
Vol 11 (5) ◽  
pp. 87-90 ◽  
Author(s):  
A. B. Baranov ◽  
O. E. Peksimov ◽  
T. N. Prudskova ◽  
T. A. Andreeva ◽  
I. D. Simonov-Emelyanov ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Flow Behavior ◽  
Linear Thermal Expansion ◽  
State Equation ◽  
Rheological Characteristics ◽  
Temperature Range ◽  
Foreign Brand ◽  
Different Temperatures ◽  
First Time

The research covers rheological characteristics of melts of polysulfones of domestic brand PSF-190 and foreign brand Udel P-1700 at temperatures ranging from 290 to 360°C. The values of activation energy of viscous flow of polysulfone melts at different temperatures are presented. The flow behavior indexes of melts of polysulfones PSF-190 and Udel P-1700 were determined. For the first time thermal stability curves over a wide temperature range were obtained, and formulas for describing them were presented. Temperature modes for processing the studied polysulfones were suggested. The dependency of density and volume in the temperature range from 23 to 320°C were obtained by the dilatometric method. Besides, constants and coefficients of the state equation of linear thermal expansion were calculated.

scholarly journals Электропроводность монокристаллов MnGaInSе-=SUB=-4-=/SUB=- на переменном токе

2020 ◽  
Vol 46 (11) ◽  
pp. 19
Author(s):  
Н.Н. Нифтиев ◽  
Ф.М. Мамедов ◽  
М.Б. Мурадов
Keyword(s):  
Electrical Conductivity ◽  
Single Crystal ◽  
Frequency Dependence ◽  
Electric Current ◽  
Single Crystals ◽  
Activation Energies ◽  
Temperature Range ◽  
Temperature Dependences ◽  
Alternating Electric Current

The results of studying the frequency and temperature dependences of the electrical conductivity of MnGaInSe4 single crystals on alternating electric current are presented. It was found that in the temperature range of 295.5–360 K at frequencies of 2•104–106 Hz, the regularity σ ∼ fS (0.1≤ s≤1.0) holds for electrical conductivity. It is shown that in the MnGaInSe4 single crystal the frequency dependence of electrical conductivity can be explained using the multiplet model, and the conductivity in these single crystals is characterized by a band-hop mechanism. Based on the dependences log σ ∼ 103/T, the activation energies are determined.

scholarly journals Электропроводность структур металл--диэлектрик--полупродник на основе сегнетоэлектрических пленок

2020 ◽  
Vol 62 (1) ◽  
pp. 121
Author(s):  
М.С. Афанасьев ◽  
Е.И. Гольдман ◽  
Г.В. Чучева ◽  
А.Э. Набиев ◽  
Дж.И. Гусейнов ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Charge Transfer ◽  
Fermi Level ◽  
Average Distance ◽  
Experimental Studies ◽  
Frequency Range ◽  
Ferroelectric Films ◽  
Hopping Mechanism ◽  
Semiconductor Structures ◽  
Temperature Dependences

Abstract In this paper, we present the results of experimental studies of the frequency and temperature dependences of the electrical conductivity of metal–dielectric–semiconductor structures based on ferroelectric films of the Ba_0.8Sr_0.2TiO_3 composition. In the temperature range of 290–400 K and the frequency range of 25–10^6 Hz, the conductivity was found to obey the σ ∝ f  ^0.76 law, which is characteristic of the hopping mechanism of charge transfer over states localized near the Fermi level. The density of these states, average distance and time of jumps are estimated.

Intrinsic and Dopant-Enhanced Solid Phase Epitaxy in Amorphous Germanium

2008 ◽  
Vol 1070 ◽  
Author(s):  
Brett Cameron Johnson ◽  
Paul Gortmaker ◽  
Jeffrey C. McCallum
Keyword(s):  
Activation Energy ◽  
Ion Implantation ◽  
Fermi Level ◽  
Concentration Profile ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Amorphous Germanium ◽  
Time Resolved ◽  
Temperature Range ◽  
Kinetics Of

ABSTRACTThe kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) are studied in thick amorphous germanium (a-Ge) layers formed by ion implantation on <100> Ge substrates. The SPE rates for H-free Ge were measured with a time-resolved reflectivity (TRR) system in the temperature range 300 – 540 °C and found to have an activation energy of (2.15 ± 0.04) eV. Dopant enhanced SPE was measured in a-Ge layers containing a uniform concentration profile of implanted As spanning the concentration regime 1 – 10 × 1019 cm3. The generalized Fermi level shifting model shows excellent fits to the data.

Kinetics of Cu Segregation in Al-Cu(1at% Cu) Interconnects Studied by Resistance Measurements

1997 ◽  
Vol 473 ◽  
Author(s):  
A. J. Kalkman ◽  
A. H. Verbruggen ◽  
G. C. A. M. Janssen ◽  
S. Radelaar
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Grain Boundary ◽  
Room Temperature ◽  
Boundary Diffusion ◽  
Measurement Temperature ◽  
Temperature Range ◽  
Different Temperatures ◽  
Resistance Decrease ◽  
Kinetics Of

ABSTRACTThe time-dependence of the growth of Al2Cu precipitates in Al-Cu(lat% Cu) thin films is studied by means of resistance measurements at different temperatures. The samples are annealed at 400°C for 1 hour, and then quickly cooled down to room temperature. Afterwards, the samples are heated within one minute to a measurement temperature between 140 °C and 240 °C. Growth of precipitates causes a well defined decrease in resistance. The observed resistance decrease does not follow an exponential decay. In the investigated temperature range the resistance decrease can be accurately modelled by (R(t)-R∞) = (Ro-R∞)exp(-(t /τ)n), with the time constant τ= τ0 exp(Ea / kT). Excellent fits were obtained resulting in n = 0.66±0.05, independent of temperature, and Ea= 0.81±0.03 eV. This value for the activation energy agrees very well with the activation energy that has been reported in literature for both electromigration failure in Al-Cu and grain-boundary diffusion of Cu in Al. The value we found for n is intriguingly close to 2/3 and deviates strongly from the values of n reported for bulk Al-Cu (n = 1.5–1.8) in the same temperature range.

LOW TEMPERATURE STUDIES OF THE DIELECTRIC AND ELECTRICAL PARAMETERS OF GLASSY Se90Ge10-xInx

2002 ◽  
Vol 09 (03n04) ◽  
pp. 1379-1385
Author(s):  
S. ABOU EL-HASSAN
Keyword(s):  
Activation Energy ◽  
Dielectric Properties ◽  
Low Temperature ◽  
Localized States ◽  
Frequency Range ◽  
Electrical Parameters ◽  
Cbh Model ◽  
Correlated Barrier Hopping ◽  
Density Of Localized States ◽  
Different Temperatures

The dielectric properties of the system Se 90 Ge 10-x In x (x = 2, 4 and 6 at. %) were studied in the temperature range of 78–273 K and in the frequency range of 400 Hz–20 kHz. The density of localized states N(E) and the activation energy of hopping wk for the samples were deduced at different temperatures. The exponents s, m1 and m2 of the equations σ ac (ω) = Aωs, ε′ = Bωm1 and ε′′ = Cωm2 have been deduced for the samples. The composition and temperature dependence of s, m1, m2, wk and N(E) have been determined. The results are interpreted in terms of the correlated barrier hopping (CBH) model and the concept of localized states.

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