scholarly journals Effect of Heat Treatment on the Bulk Etch Rate Activation Energy of CR-39 Detector

2016 ◽  
Vol 11 (4) ◽  
pp. 70-83
Author(s):  
Ahmed A. I. AL-Obedy ◽  
Nada M. Hassan
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Etch Rate ◽  
Bulk Etch Rate

Effects of UV irradiation on Fission-fragment track parameters in Makrofol-E detector

2019 ◽  
Vol 28 (12) ◽  
pp. 1950110 ◽  
Author(s):  
R. K. Jain ◽  
S. Kumar ◽  
A. Kumar ◽  
Aniket Kumar ◽  
M. K. Singh ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Fission Fragment ◽  
Etch Rate ◽  
Activation Energies ◽  
Track Detector ◽  
Nuclear Track Detector ◽  
Bulk Etch Rate ◽  
Track Etch Rate ◽  
Track Etch

This study gives information about the effects of UV (here, the wavelength is 160 nm) exposure on the bulk etch rate ([Formula: see text], track etch rate ([Formula: see text], the detector sensitivity ([Formula: see text], critical angle ([Formula: see text] and etching efficiency ([Formula: see text] of Makrofol-E Solid State Nuclear Track Detector. The effect of UV on the activation energy of Makrofol-E was also studied. Nine pieces of Makrofol-E Solid State Nuclear Track Detector were separated into three equal sets as set A, set B and set C. Set A, named as reference set (Fission fragment FF), was irradiated to [Formula: see text]Cf source. Set B, called as post-exposed ([Formula: see text]), was first irradiated to [Formula: see text]Cf and then exposed to UV. The process was reversed for set C named as pre-exposed ([Formula: see text]) at the same conditions. From the results, it is concluded that radiation produces small but significant effect on activation energy [Formula: see text] of bulk etch rate for pre-exposed and post-exposed samples. Also, the activation energies [Formula: see text] of track etch rate for post-exposed and Fission fragment samples are within experimental uncertainty. The energy carried by UV radiation may be responsible for cross networking processes occurring during the exposure which results small change in activation energies for both [Formula: see text] and [Formula: see text]. The [Formula: see text] can be increased by hardening detector material of the pre-exposed detector.

Magnetic Properties, Nanostructure, and Ordering Kinetics of Nb Additive FePtCu Films

2010 ◽  
Vol 638-642 ◽  
pp. 1743-1748
Author(s):  
G.J. Chen ◽  
Y.H. Shih ◽  
Jason S.C. Jang ◽  
S.R. Jian ◽  
P.H. Tsai ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Magnetic Properties ◽  
Heating Rates ◽  
Fept Alloy ◽  
Ordering Kinetics ◽  
Nb Content ◽  
Kinetics Of ◽  
Nb Addition ◽  
Microstructure And Magnetic Properties

In this study,the (FePt)94-xCu6Nbx (x=0, 2.87, 4.52, 5.67) alloy films were prepared by co-sputtering. The effects of Nb addition content and heat treatment on the microstructure and magnetic properties of the polycrystalline FePtCu films are reported. Our previous experiments showed that the ordering temperature of the (FePt)94Cu6 films reduced to 320 °C, which is much lower than that of the FePt alloy. However, the grain growth after heat treatment limited the practical application in recording media. By adding the Nb content in the (FePt)94Cu6 film, the grain sizes of the films can be adjusted from 50 to 18nm, even for the films annealed at temperature as high as 600°C. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, revealed that the addition of Nb enhanced the activation energy of ordering from 87 kJ/mol to 288 kJ/mol for the (FePt)94-xCu6Nbx (x=0 and 2.87, respectively) films. The reduction of the grain size and the corresponding increase in the activation energy of the Fe-Pt-Cu-Nb films might result from the precipitation of the Nb atoms around the ordering FePt phase. The (FePt)94-xCu6Nbx (x=2.87) film showed a coercive force of 13.4 kOe and the magnetization of 687 emu/cc.

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

2012 ◽  
Vol 727-728 ◽  
pp. 163-168 ◽  
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.

Defect Spectroscopy on Damp-Heat Treated ZnO/CdS/Cu(In,Ga)(S,Se)2/Mo Heterojunction Solar Cells

2003 ◽  
Vol 58 (12) ◽  
pp. 691-702 ◽  
Author(s):  
C. Deibel ◽  
V. Dyakonov ◽  
J. Parisi
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Solar Cells ◽  
Deep Level ◽  
Heat Exposure ◽  
Continuous Distribution ◽  
Open Circuit ◽  
Defect States ◽  
Band Bending ◽  
Test Cells

The changes of defect characteristics induced by accelerated lifetime tests on solar cells of the heterostructure ZnO/CdS/Cu(In,Ga)(S,Se)2/Mo are investigated. Encapsulated modules were shown to be stable against water vapor and oxygen under outdoor conditions, whereas the fill factor and open-circuit voltage of non-encapsulated test cells are reduced after prolonged damp heat treatment in the laboratory, leading to a reduced energy conversion efficiency. We subjected non-encapsulated test cells to extended damp heat exposure at 85 ◦C ambient temperature and 85% relative humidity for various time periods (6 h, 24 h, 144 h, 294 h, and 438 h). In order to understand the origin of the pronounced changes of the cells, we applied temperature-dependent current-voltage and capacitance voltage measurements, admittance spectroscopy, and deep-level transient spectroscopy. We observed the presence of electronic defect states which show an increasing activation energy due to damp heat exposure. The corresponding attempt-to-escape frequency and activation energy of these defect states obey the Meyer-Neldel relation. We conclude that the response originates from an energetically continuous distribution of defect states in the vicinity of the CdS/chalcopyrite interface. The increase in activation energy indicates a reduced band bending at the Cu(In,Ga)(S,Se)2 surface.We also observed changes in the bulk defect spectra due to the damp-heat treatment. - PACS: 73.20.hb, 73.61.Le

Predictive Kinetics-based Model for Shock-activated Reaction Synthesis of Ti3SiC2

2005 ◽  
Vol 20 (6) ◽  
pp. 1476-1484
Author(s):  
Jennifer L. Jordan ◽  
John A. Pelesko ◽  
Naresh N. Thadhani
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Steady State ◽  
Predictive Model ◽  
Heat Dissipation ◽  
Experimental Results ◽  
Reaction Synthesis ◽  
Synthesis Conditions ◽  
Type Reaction ◽  
Activated State

A kinetics model based on mass and heat transport has been developed for Ti3SiC2 formation via shock-activated reaction synthesis of powder precursors. The model allows prediction of heat treatment conditions under which an otherwise steady-state reaction is taken over by a “run-away” combustion-type reaction during post-shock reaction synthesis of Ti3SiC2. Shock compression of Ti, SiC, and graphite precursors generates a densely packed highly activated state of reactants, which lowers the activation energy and results in an increased rate of formation of Ti3SiC2 at a lower temperature and in shorter times. The predictive model correlated with experimental results of fraction reacted as a function of time at heat-treatment temperatures of 1400 and 1600 °C illustrates an increased rate of reaction due to lowering activation energy, which also results in the reaction at 1600 °C being taken over by a “run-away” combustion-type reaction, as the rate of heat release due to reaction exceeds the rate of heat dissipation through the compact. Correlation of the model with experimental results illustrates that the predictive model can be used to optimize reaction synthesis conditions in shock-densified compacts of Ti3SiC2-forming powder precursors, to better understand the processes leading to a steady-state reaction being taken over by the combustion mode.

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