Measuring temperature-dependent activation energy in thermally activated processes: A 2D Arrhenius plot method

2010 ◽  
Vol 81 (3) ◽  
pp. 033910 ◽  
Author(s):  
Jian V. Li ◽  
Steven W. Johnston ◽  
Yanfa Yan ◽  
Dean H. Levi
Keyword(s):  
Activation Energy ◽  
Arrhenius Plot ◽  
Temperature Dependent ◽  
Thermally Activated ◽  
Activated Processes ◽  
Arrhenius Plot Method

scholarly journals The Electronic Transport Mechanism in Amorphous Tetrahedrally-Coordinated Carbon Films

1997 ◽  
Vol 498 ◽  
Author(s):  
J. P. Sullivan ◽  
T. A. Friedmann ◽  
R. G. Dunn ◽  
E. B. Stechel ◽  
P. A. Schultz ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Stress Relaxation ◽  
Electronic Transport ◽  
Transport Mechanism ◽  
Thermal Evolution ◽  
Carbon Films ◽  
Temperature Dependent ◽  
Thermally Activated ◽  
Relaxation Measurements

ABSTRACTThe electronic transport mechanism in tetrahedrally-coordinated amorphous carbon was investigated using measurements of stress relaxation, thermal evolution of electrical conductivity, and temperature-dependent conductivity measurements. Stress relaxation measurements were used to determine the change in 3-fold coordinated carbon concentration, and the electrical conductivity was correlated to this change. It was found that the conductivity was exponentially proportional to the change in 3-fold concentration, indicating a tunneling or hopping transport mechanism. It was also found that the activation energy for transport decreased with increasing anneal temperature. The decrease in activation energy was responsible for the observed increase in electrical conductivity. A model is described wherein the transport in this material is described by thermally activated conduction along 3-fold linkages or chains with variable range and variable orientation hopping. Thermal annealing leads to chain ripening and a reduction in the activation energy for transport.

Thermally Activated Processes in CaMoO4 Crystals

2013 ◽  
Vol 200 ◽  
pp. 220-224 ◽  
Author(s):  
Volodymyr Tsybulskyi ◽  
Myron R. Panasyuk ◽  
Ivan M. Solskii ◽  
Viktor Rudyk ◽  
Volodymyr B. Kapustianyk
Keyword(s):  
Activation Energy ◽  
Glow Curve ◽  
High Temperature Annealing ◽  
Thermally Stimulated Luminescence ◽  
Absorption Bands ◽  
X Ray ◽  
Thermally Activated ◽  
Calcium Molybdate ◽  
Activated Processes ◽  
Thermally Stimulated Depolarization

The effect of annealing in the oxygen flow atmosphere of calcium molybdate crystals on their absorption spectra and thermally stimulated luminescence (TSL) glow curve was studied. The thermally stimulated depolarization (TSD), polarization (TSP) currents and temperature dependence of X-ray luminescence of CaMoO4were investigated in the temperature range of 100-320 K. One of the trap detected by TSL was found to disappear after high-temperature annealing of calcium molybdate single crystals. The nature of the absorption bands is discussed. The values of activation energy were calculated for the detected traps.

Defects Study by Activation Energy Profile for Lowering Leakage Current in P-N Junction

2011 ◽  
Vol 695 ◽  
pp. 569-572 ◽  
Author(s):  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Poopol Rujanapich ◽  
Narin Atiwongsangthong ◽  
Surasak Niemcharoen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Leakage Current ◽  
Volume Diffusion ◽  
Defect Density ◽  
Arrhenius Plot ◽  
Temperature Dependent ◽  
Residual Defect ◽  
Current Voltage ◽  
Depletion Width ◽  
Capacitance Voltage

Diode leakage current consists of diffusion (Id) and generation current (Ig), which is strongly sensitive to the residual defect density. These defects can be studied by activation energy (Ea). Therefore, this paper presents a method for calculating activation energy of silicon p-n junctions from volume generation current. It combines temperature-dependent current–voltage (I –V) and capacitance–voltage (C-V) measurements of diodes. The Igcan be found from the volume leakage current by subtraction of the volume diffusion current, which is calculated while the depletion width is zero. The activation energy (Ea) is derived from slope of an Arrhenius plot of Ig. To derive the correct slope the temperature dependence of the depletion width, which is obtained from the corrected volume capacitance has been applied. The Ea profile below junction has been shown. The lower Ea value has been found near the junction, which may relate to the junction implantation.

scholarly journals Tetragonal–Cubic Phase Transition and Low-Field Dielectric Properties of CH3NH3PbI3 Crystals

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4215
Author(s):  
Roxana E. Patru ◽  
Hamidreza Khassaf ◽  
Iuliana Pasuk ◽  
Mihaela Botea ◽  
Lucian Trupina ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Current Knowledge ◽  
Cubic Phase ◽  
Relaxation Processes ◽  
Temperature Dependent ◽  
Thermally Activated ◽  
Low Field ◽  
Conduction Mechanisms ◽  
Temperature Ranges ◽  
Nyquist Plots

The frequency and temperature dependence of dielectric properties of CH3NH3PbI3 (MAPI) crystals have been studied and analyzed in connection with temperature-dependent structural studies. The obtained results bring arguments for the existence of ferroelectricity and aim to complete the current knowledge on the thermally activated conduction mechanisms, in dark equilibrium and in the presence of a small external a.c. electric field. The study correlates the frequency-dispersive dielectric spectra with the conduction mechanisms and their relaxation processes, as well as with the different transport regimes indicated by the Nyquist plots. The different energy barriers revealed by the impedance spectroscopy highlight the dominant transport mechanisms in different frequency and temperature ranges, being associated with the bulk of the grains, their boundaries, and/or the electrodes’ interfaces.

Temperature-dependent activation energy and variable range hopping in semi-insulating GaAs

2006 ◽  
Vol 21 (12) ◽  
pp. 1681-1685 ◽  
Author(s):  
R M Rubinger ◽  
G M Ribeiro ◽  
A G de Oliveira ◽  
H A Albuquerque ◽  
R L da Silva ◽  
...  
Keyword(s):  
Activation Energy ◽  
Variable Range Hopping ◽  
Temperature Dependent ◽  
Variable Range

Hydrogenation of methylacetylene. III. The reaction of methylacetylene with hydrogen catalyzed by nickel, copper, and their alloys

1968 ◽  
Vol 46 (4) ◽  
pp. 623-633 ◽  
Author(s):  
R. S. Mann ◽  
K. C. Khulbe
Keyword(s):  
Activation Energy ◽  
Nickel Catalyst ◽  
Hydrogen Pressure ◽  
Constant Volume ◽  
Temperature Dependent ◽  
Nickel Copper ◽  
Wide Range ◽  
Initial Hydrogen Pressure

The reaction between methylacetylene and hydrogen over unsupported nickel, copper, and their alloys has been investigated in a static constant volume system between 20 and 220 °C for a wide range of reactant ratios. The order of reaction with respect to hydrogen was one and nearly independent of temperature. While the order of reaction with respect to methylacetylene over nickel catalyst was slightly negative and temperature dependent, it was always positive and nearly independent of temperature for copper and copper-rich alloys. Selectivity was independent of initial hydrogen pressure for nickel and copper only; for others it decreased rapidly with increasing hydrogen pressure. The overall activation energy varied between 9 and 21.2 kcal/g mole. Selectivity and extent of polymerization increased with increasing amount of copper in the alloy.

Analysis of Tempering and Rehardening for Grinding of Hardened Steels

1991 ◽  
Vol 113 (4) ◽  
pp. 388-394 ◽  
Author(s):  
O. B. Fedoseev ◽  
S. Malkin
Keyword(s):  
Thermal Properties ◽  
Heat Source ◽  
Hardened Steel ◽  
Temperature History ◽  
Hardness Distribution ◽  
Temperature Dependent ◽  
Thermally Activated ◽  
Reaction Equations ◽  
Rate Controlling Step ◽  
Good Agreement

An analysis is presented to predict the hardness distribution in the subsurface of hardened steel due to tempering and rehardening associated with high temperatures generated in grinding. The grinding temperatures are modeled with a triangular heat source at the grinding zone and temperature-dependent thermal properties. The temperature history, including the effect of multiple grinding passes, is coupled with thermally activated reaction equations for tempering and for reaustenitization which is the rate controlling step in rehardening. Experimental results from the literature are found to be in good agreement with the analytical predictions.

Validation of New Mathematical Model of Flank Wear by Different Methods

2012 ◽  
Vol 729 ◽  
pp. 169-174 ◽  
Author(s):  
Zoltán Pálmai ◽  
Márton Takács ◽  
Balázs Zsolt Farkas
Keyword(s):  
Activation Energy ◽  
Mathematical Model ◽  
Flank Wear ◽  
Technological Parameters ◽  
Wear Process ◽  
Oxidation Processes ◽  
Industrial Manufacturing ◽  
Thermally Activated ◽  
Optical Electron ◽  
The Mean

Having reviewed the literature on cutting and based on the optical, electron-optical and morphological examinations of wear processes we have reached the conclusion that it is possible to describe the abrasive, adhesive and thermally activated diffusion, oxidation processes in a single mathematical model. The model is a non-linear autonomous differential equation, which can be solved by simple numerical methods. The complex wear equation was validated by the results of the cutting tests performed with P20 carbide on C45 carbon steel. If we have this data, we can calculate the activation energy of the process determining the nature of the wear process. The apparent activation energy of wear is Q=151,7kJ/mol. The model can even be used with changing technological parameters, and the data necessary for the constants of the wear equation may as well be determined even by measurements performed on the tool during industrial manufacturing. By the mean of this data, we can calculate the activation energy determining the nature of the wear process.

ON THE DIELECTRIC BEHAVIOR OF LiCo3/5Fe2/5VO4 CERAMICS

2010 ◽  
Vol 24 (07) ◽  
pp. 665-670
Author(s):  
MOTI RAM
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Frequency Dependence ◽  
Chemical Method ◽  
Arrhenius Plot ◽  
Dielectric Behavior ◽  
Tangent Loss ◽  
Low Frequencies ◽  
Different Temperatures ◽  
Tan Δ

The LiCo 3/5 Fe 2/5 VO 4 ceramics has been fabricated by solution-based chemical method. Frequency dependence of the dielectric constant (εr) at different temperatures exhibits a dispersive behavior at low frequencies. Temperature dependence of εr at different frequencies indicates the dielectric anomalies in εr at Tc (transition temperature) = 190°C, 223°C, 263°C and 283°C with (εr) max ~ 5370, 1976, 690 and 429 for 1, 10, 50 and 100 kHz, respectively. Frequency dependence of tangent loss ( tan δ) at different temperatures indicates the presence of dielectric relaxation in the material. The value of activation energy estimated from the Arrhenius plot of log (τd) with 103/T is ~(0.396 ± 0.012) eV.

Magnetic properties of undoped and Co-doped n-type β–FeSi2.5 single crystals

2002 ◽  
Vol 17 (11) ◽  
pp. 2960-2965 ◽  
Author(s):  
E. Arushanov ◽  
L. Ivanenko ◽  
D. Eckert ◽  
G. Behr ◽  
U. K. Rößler ◽  
...  
Keyword(s):  
Activation Energy ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
External Field ◽  
Single Crystals ◽  
Spin Glasses ◽  
Paramagnetic Centers ◽  
Temperature Dependent ◽  
Paramagnetic Curie Temperature ◽  
Co Doped

Results of magnetization and magnetic susceptibility measurements on undoped and Co-doped FeSi2.5 single crystals are presented. The temperature dependence of the magnetic susceptibility of the Co-doped sample in the range of 5–300 K can be explained by temperature-dependent contributions due to paramagnetic centers and the carriers excited thermally in the extrinsic conductivity region. The values of the paramagnetic Curie temperature and activation energy of the donor levels were estimated. It is also shown that the magnetic susceptibility of Co-doped samples cooled in zero external field and in a field are different. This resembles the properties of spin-glasses and indicates the presence of coupling between magnetic centers.

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