Activation Energy Measurement of Cu/SS-AlN/SiAlOx Solar Selective Absorbing Coating

Activation energy is an important parameter which determines thermal stability of solar selective absorbing coating. In this investigation, a new performance criterion (PC) was defined for solar selective coating according to our modified equation of photo-thermal conversion. Then the activation energy of Cu/stainless steel (SS)-AlN/SiAlOxsolar selective absorbing coating was measured. Cu/SS-AlN/SiAlOxtandem films were deposited by magnetron sputtering. Accelerated ageing tests were performed on the coating at 500°C and 550°C, under the atmosphere, calculatingPCfrom the reflectance spectrum and measuring the failure time. According to Arrhenius equation, the activation energy and the equivalent life span of Cu/SS-AlN/SiAlOxtandem film at 400°C were determined to be about 187.4kJ/moland more than 16260 hours, respectively.

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Thermal Stability of Chromium-Iron Oxidation Mixture Cermet-Based Solar Selective Absorbing Coatings

Molecules ◽

10.3390/molecules25051178 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1178 ◽

Cited By ~ 1

Author(s):

Hongwen Yu ◽

Jinkai Li ◽

Qian Zhang ◽

Wei Pang ◽

Hui Yan ◽

...

Keyword(s):

Thermal Stability ◽

Iron Oxidation ◽

Optical Trap ◽

Thermal Conversion ◽

Performance Criterion ◽

Solar Thermal ◽

Solar Absorptance ◽

Solar Thermal System ◽

First Time ◽

Thermal Stability Of

The solar selective absorber coating (SSAC) are at the core of the efficient solar-thermal system. In this paper, for the first time, the Chromium-iron oxidation mixture cermet was successfully prepared on the surface of ultra-pure ferritic stainless steel by chemical coloring as SSAC. The coating surface has an optical trap structure, and the chromium-iron oxidation mixture cermet is used as an absorption layer to realize solar-thermal conversion. The solar absorptance (AM1.5) of the coating reached 93.66, and the thermal emittance was less than 13. After thermal shock tests at 25/300 °C done 32 times (accumulated 812.8 h), the Performance Criterion (PC) of the coating was 0.01375 < 0.05, showing outstanding thermal stability.

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Cr-Substituted Mesoporous Aluminophosphate Molecular Sieve: Synthesis, Characterization, Crystallization Kinetics and Catalytic Activity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.316-317.1018 ◽

2013 ◽

Vol 316-317 ◽

pp. 1018-1023

Author(s):

Xin Zhu Li ◽

Ji Shi Zhang

Keyword(s):

Activation Energy ◽

Catalytic Activity ◽

Crystal Growth ◽

Crystallization Kinetics ◽

Molecular Sieve ◽

Arrhenius Equation ◽

Degree Of Crystallinity ◽

Tert Butylhydroperoxide ◽

Growth Activation ◽

Cr Map

Cr-substituted mesoporous aluminophosphate molecular sieve (Cr-MAP) was synthesized and characterized. Crystallization kinetics curves measured as an index to the relative degree of crystallinity, according to the Arrhenius equation to calculate the apparent nucleation activation energy and crystal growth activation energy of Cr-MAP, which was 63.7 and 14.7 kJ• mol-1, respectively. Cr-MAP had highly catalytic activity for fabricating acetophenone by selectively oxizing ethylbenzene. Using tert-butylhydroperoxide as oxidant and chlorobenzene as solvent at 100 °C for 8 h, acetophenone selectivity, acetophenone yield and ethylbenzene conversion reaches 85.4, 62.2 and 72.8 %, respectively.

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Diffusion Coefficients of Interest for the Simulation of Heat Treatment in Rare-Earth Transition Metal Magnets

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.163 ◽

2012 ◽

Vol 727-728 ◽

pp. 163-168 ◽

Cited By ~ 4

Author(s):

Marcos Flavio de Campos

Keyword(s):

Experimental Data ◽

Heat Treatment ◽

Activation Energy ◽

Rare Earth ◽

Transition Metal ◽

Impurity Atom ◽

Diffusion Coefficients ◽

Arrhenius Equation ◽

Atom Diffusion ◽

Essential Input

In the case of the modeling of sintering and heat treatments, the diffusion coefficients are an essential input. However, experimental data in the literature about diffusion coefficients for rare-earth transition metal intermetallics is scarce. In this study, the available data concerning diffusion coefficients relevant for rare-earth transition metal magnets are reviewed and commented. Some empirical rules are discussed, for example the activation energy is affected by the size of the diffusing impurity atom. Diffusion coefficients for Dy, Nd and Fe into Nd2Fe14B are given according an Arrhenius equation D=D0exp (-Q/RT). For Dy diffusion into Nd2Fe14B, Q 315 kJ/mol and D08 . 10-4m2/s.

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Meyer-Neldel Rule on thermal stability parameters (trap depth and frequency factor) of luminescence signals in quartz

10.5194/egusphere-egu21-10775 ◽

2021 ◽

Author(s):

Zuzanna Kabacińska ◽

Alida Timar-Gabor ◽

Benny Guralnik

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Hydrogen Diffusion ◽

Dose Range ◽

Accurate Determination ◽

Frequency Factor ◽

Proton Conduction ◽

High Dose ◽

Compensation Law ◽

Thermal Stability Of

Thermally activated processes can be described mathematically by the Arrhenius equation. The Meyer-Neldel Rule (MNR), or compensation law, linearly relates the pre-exponent term to the logarithm of the excitation enthalpy for processes that are thermally driven in an Arrhenian manner. This empirical rule was observed in many areas of materials science, in physics, chemistry, and biology. In geosciences it was found to uphold in hydrogen diffusion (Jones 2014a) and proton conduction (Jones 2014b) in minerals.Trapped charge dating methods that use electron spin resonance (ESR) or optically or thermally stimulated luminescence (OSL and TL) are based on the dose-dependent accumulation of defects in minerals such as quartz and feldspar. The thermal stability of these defects in the age range investigated is a major prerequisite for accurate dating, while the accurate determination of the values of the trap depths and frequency factors play a major role in thermochronometry applications.&#160;The correlation of kinetic parameters for diffusion has been very recently established for irradiated oxides (Kotomin et al. 2018). A correlation between the activation energy and the frequency factor that satisfied the Meyer&#8211;Neldel rule was reported when the thermal stability of [AlO4/h+]0 and [TiO4/M+]0 ESR signals in quartz was studied as function of dose (Benzid and Timar-Gabor 2020). Here we compiled the optically stimulated luminescence (OSL) data published so far in this regard, and investigated experimentally the thermal stability of OSL signals for doses ranging from 10 to 10000 Gy in sedimentary quartz samples. We report a linear relationship between the natural logarithm of the preexponent term (the frequency factor) and the activation energy E, corresponding to a Meyer-Neldel energy of 45 meV, and a deviation from first order kinetics in the high dose range accompanied by an apparent decrease in thermal stability. The implications of these observations and the atomic and physical mechanisms are currently studied.&#160;ReferencesBenzid, K., Timar Gabor, A. 2020. The compensation effect (Meyer&#8211;Neldel rule) on [AlO4/h+]0 and [TiO4/M+]0 paramagnetic centers in irradiated sedimentary quartz. AIP Advances 10, 075114.Kotomin, E., Kuzovkov, V., Popov, A. I., Maier, J., and Vila, R. 2018. Anomalous kinetics of diffusion-controlled defect annealing in irradiated ionic solids. J. Phys. Chem. A 122(1), 28&#8211;32Jones, A. G. (2014a), Compensation of the Meyer-Neldel Compensation Law for H diffusion in minerals, Geochem. Geophys. Geosyst., 15, 2616&#8211;2631Jones, A. G. (2014b), Reconciling different equations for proton conduction using the Meyer-Neldel compensation rule, Geochem. Geophys. Geosyst., 15, 337&#8211;349

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Thermal Stability of Ultrafine-Grained Pure Titanium Processed by High-Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.338 ◽

2021 ◽

Vol 1016 ◽

pp. 338-344

Author(s):

Wan Ji Chen ◽

Jie Xu ◽

De Tong Liu ◽

De Bin Shan ◽

Bin Guo ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Grain Size ◽

High Pressure ◽

Annealing Temperature ◽

High Pressure Torsion ◽

Stored Energy ◽

Ultrafine Grained ◽

Average Grain Size ◽

Thermal Stability Of

High-pressure torsion (HPT) was conducted under 6.0 GPa on commercial purity titanium up to 10 turns. An ultrafine-grained (UFG) pure Ti with an average grain size of ~96 nm was obtained. The thermal properties of these samples were studied by using differential scanning calorimeter (DSC) which allowed the quantitative determination of the evolution of stored energy, the recrystallization temperatures, the activation energy involved in the recrystallization of the material and the evolution of the recrystallized fraction with temperature. The results show that the stored energy increases, beyond which the stored energy seems to level off to a saturated value with increase of HPT up to 5 turns. An average activation energy of about 101 kJ/mol for the recrystallization of 5 turns samples was determined. Also, the thermal stability of the grains of the 5 turns samples with subsequent heat treatments were investigated by microstructural analysis and Vickers microhardness measurements. It is shown that the average grain size remains below 246 nm when the annealing temperature is below 500 °C, and the size of the grains increases significantly for samples at the annealing temperature of 600 °C.

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Synthesis of Fe-rich Fe–Al nanocrystalline solid solutions using ball milling

Journal of Materials Research ◽

10.1557/jmr.1999.0238 ◽

1999 ◽

Vol 14 (5) ◽

pp. 1760-1770 ◽

Cited By ~ 18

Author(s):

H. G. Jiang ◽

H. M. Hu ◽

E. J. Lavernia

Keyword(s):

Heat Treatment ◽

Activation Energy ◽

Thermal Stability ◽

Intermetallic Compound ◽

Ball Milling ◽

Microstructural Evolution ◽

Solid Solutions ◽

Al Alloys ◽

Time Intervals ◽

Thermal Stability Of

The synthesis of nanocrystalline Fe, Fe–4 wt% Al, and Fe–10 wt% Al solid solutions by SPEX ball milling has been studied. The microstructural evolution during ball milling, as well as subsequent heat treatment, has been characterized. The results demonstrate that ball milling promotes the formation of αFe–4 wt% Al and αFe–10 wt% Al solid solutions by reducing the activation energy of these alloys and generating thermal energy during this process. For Fe–10 wt% Al powders milled for various time intervals up to approximately 20 min, the FeAl intermetallic compound is formed. For alloys annealed at temperatures ranging from 600 to 1000 °C, the addition of 10 wt% Al to Fe significantly enhances the thermal stability of the nanocrystalline Fe–Al alloys. Interestingly, the addition of Al within the range of 4–10 wt% seems to have little effect on the thermal stability of these alloys annealed under the same conditions. Also, the thermal stability improves for alloys milled in air as opposed to those processed using Ar.

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Viscosity Of Molten Rare Earth Metal Trichlorides I. Cecl3, Ndcl3, Smcl3, Dycl3 And Ercl3

Zeitschrift für Naturforschung A ◽

10.1515/zna-2003-7-812 ◽

2003 ◽

Vol 58 (7-8) ◽

pp. 457-463 ◽

Cited By ~ 2

Author(s):

A. Potapov ◽

V. Khokhlov ◽

Y. Satoa

Keyword(s):

Activation Energy ◽

Rare Earth ◽

Viscous Flow ◽

Rare Earth Metal ◽

Dynamic Viscosity ◽

Kinematic Viscosity ◽

Arrhenius Equation ◽

Earth Metal ◽

Capillary Viscometer ◽

Density Data

The kinematic viscosity of molten CeCl3, NdCl3, SmCl3, DyCl3 and ErCl3 has been measured by using a capillary viscometer. The dynamic viscosity was computed by using density data taken from the literature. The viscosity increases with going from CeCl3 to ErCl3. The activation energy of the viscous flow, calculated by the Arrhenius equation, rises in the same order.

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Epoxy Cured with Anhydride Terminated Polydimethylsiloxane: Cure Kinetics and Thermal Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.261 ◽

2011 ◽

Vol 415-417 ◽

pp. 261-264

Author(s):

Yuan Ren ◽

Zheng Xi ◽

Wen Jun Gan ◽

Liang Zhang ◽

Jing Zhang ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Thermal Properties ◽

Succinic Anhydride ◽

Cure Kinetics ◽

Diglycidyl Ether ◽

Scanning Calorimetry ◽

Thermogravimetric Analyses ◽

Isothermal Measurements ◽

Thermal Stability Of

A siloxane-containing dianhydride, succinic anhydride terminated polydimethylsiloxane (DMS-Z21) was selected to cure diglycidyl ether of bisphenol-A based epoxy resin (DGEBA). The cure kinetics and thermal properties were investigated by nonisothermal and isothermal differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA), respectively. The activation energy (Ea) of the curing reaction was obtained based on the methods of Kissinger and isothermal measurements. The results of the thermogravimetric analyses of the DGEBA/DMS-Z21 system showed that the thermal stability of the DGEBA/DMS-Z21 system was slightly higher than the DGEBA/MeTHPA system.

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Thermal stability of WAlN/WAlON/Al2O3-based solar selective absorber coating

MRS Advances ◽

10.1557/adv.2016.388 ◽

2016 ◽

Vol 1 (41) ◽

pp. 2807-2813 ◽

Cited By ~ 6

Author(s):

Atasi Dan ◽

Kamanio Chattopadhyay ◽

Harish C. Barshilia ◽

Bikramjit Basu

Keyword(s):

Thermal Stability ◽

Stainless Steel ◽

Stainless Steel Substrate ◽

Steel Substrate ◽

Rf Magnetron Sputtering ◽

Thermal Conversion ◽

Solar Absorptance ◽

Excellent Thermal Stability ◽

Oxidation In Air ◽

Thermal Stability Of

AbstractThe solar absorptance property of W/WAlN/WAlON/Al2O3-based coatings, deposited by DC/RF magnetron sputtering on stainless steel substrate was studied by measuring the reflectance spectra in the wavelength range of 250 - 2500 nm. The effect of thermal annealing on the optical properties of the solar selective absorber coatings was investigated. Annealing the coatings at 450°C for 150 hrs in air did not show any significant change in the spectral properties of the absorber coating indicating the excellent thermal stability of the coating. The W layer acts as infrared reflective layer and diffusion barrier on stainless steel substrate. The top Al2O3 layer serves as dense shield to protect the under layers from oxidation in air. In summary, the present study indicates the potential application of W/WAlN/WAlON/Al2O3-based selective coatings in high temperature photo thermal conversion systems.

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