Correlation of the annealing temperature for radiation damage fields to the melting point of metals in DPAD experiments

1978 ◽  
Vol 4 (1-2) ◽  
pp. 751-754 ◽  
Author(s):  
G. Schatz ◽  
P. Heubes
Keyword(s):  
Melting Point ◽  
Radiation Damage ◽  
Annealing Temperature

A Channeling Study on Mg Implanted InSb Single Crystals

1983 ◽  
Vol 27 ◽  
Author(s):  
H.W. Alberts
Keyword(s):  
Melting Point ◽  
Radiation Damage ◽  
Linear Dependence ◽  
Room Temperature ◽  
Annihilation Rate ◽  
Sharp Reduction ◽  
Complex Defect ◽  
Annealing Effects ◽  
Implantation Process ◽  
Substrate Temperatures

ABSTRACTProton and α-particle channeling were used to study the radiation damage caused by the implantation of 160 keV Mg ions in InSb. The implantations took place at various substrate temperatures ranging from room temperature to temperatures just below the melting point and doses ranging from 5.1013 to 1.1016 Mg+ cm−2. The isochronal annealing of the room temperature implanted crystals started at 200°C and damage could not be completely removed even at temperatures just below the melting point. For crystals implanted at elevated substrate temperatures no annealing effects during implantation occured up to 400°C. Above 400°C a sharp reduction of damage indicates that the rate of formation of more complex defect configurations during the implantation process becomes smaller than the annihilation rate of the vacancy-interstitial pairs. A non-linear dependence exists between the degree of radiation damage in the InSb lattice and the implanted dose.

scholarly journals The absence of metamictisation in natural monazite

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lutz Nasdala ◽  
Shavkat Akhmadaliev ◽  
Boris E. Burakov ◽  
Chutimun Chanmuang N ◽  
Radek Škoda
Keyword(s):  
High Temperature ◽  
Radioactive Waste ◽  
Radiation Damage ◽  
Alpha Particle ◽  
Annealing Temperature ◽  
Irradiation Damage ◽  
Alpha Radiation ◽  
Structural Restoration ◽  
Damage State ◽  
Damage Level

Abstract The actinide-containing mineral monazite–(Ce) is a common accessory rock component that bears petrogenetic information, is widely used in geochronology and thermochronology, and is considered as potential host material for immobilisation of radioactive waste. Natural samples of this mineral show merely moderate degrees of radiation damage, despite having sustained high self-irradiation induced by the decay of Th and U (for the sample studied herein 8.9 ± 0.3 × 1019 α/g). This is assigned to low damage-annealing temperature of monazite–(Ce) and “alpha-particle-assisted reconstitution”. Here we show that the response of monazite–(Ce) to alpha radiation changes dramatically, depending on the damage state. Only in radiation-damaged monazite–(Ce), 4He ions cause gradual structural restoration. In contrast, its high-temperature annealed (i.e. well crystalline) analogue and synthetic CePO4 experience He-irradiation damage. Alpha-assisted annealing contributes to preventing irradiation-induced amorphisation (“metamictisation”) of monazite–(Ce); however, this process is only significant above a certain damage level.

Modifications of polymers by additives and irradiations and their characterizations

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Udayan De
Keyword(s):  
Melting Point ◽  
Radiation Damage ◽  
Young’S Modulus ◽  
Positron Lifetime ◽  
Young's Modulus ◽  
Electrical Contact ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Scanning Calorimetry ◽  
Dimethyl Siloxane

Abstract Polymer properties are often engineered in desired directions by additives or by irradiations or by both. However, in space and certain other applications, energetic particles or γ-rays may damage the polymeric parts in undesired directions, needing prior radiation damage studies for necessary precautions. Case studies of three completely different polymer-additive composites follow: (1) shielding electromagnetic interference (EMI) by different composites of a polymeric binder, (2) electrical, thermal, mechanical (Young’s Modulus, Y) and positron lifetime (PL) characterizations of solid polymer electrolytes (SPEs), and (3) determination of total free volume and hole size by pressure-volume-temperature (P-V-T) and positron lifetime techniques, respectively, in two types of polymers. One type consists of complexes of poly-(ethylene oxide), PEO, with a suitable salt, PEO-salt SPEs. The other type consists of silica-filled and pure varieties of poly(dimethyl siloxane), PDMS. Melting point and glass transition temperature of these polymers have been determined from PL techniques as well as from differential scanning calorimetry (DSC). Electrical contact problem has been addressed by measuring impedance as a function of pressure, p, and then extracting p=0 values of impedance and Young’s Modulus. These illustrative measurements have been carried out for better characterization of the polymers. DSC thermogram showed that radiation induced changes of melting point of PEO-salt samples are in opposite directions for 160 MeV Ne6+ion and 1.25 MeV γ-ray irradiations. This interesting feature hints at different mechanisms of radiation damage in two cases.

scholarly journals Effect of Annealing Temperature on the Morphology and Piezoresponse Characterisation of Poly(vinylidene fluoride-trifluoroethylene) Films via Scanning Probe Microscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
K. Lau ◽  
Y. Liu ◽  
H. Chen ◽  
R. L. Withers
Keyword(s):  
Melting Point ◽  
Annealing Temperature ◽  
Vinylidene Fluoride ◽  
Hysteresis Loops ◽  
Piezoresponse Force Microscopy ◽  
Scanning Probe ◽  
Force Microscopy ◽  
Poly Vinylidene Fluoride ◽  
Probe Microscope ◽  
Small Grains

Poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE (70/30)) films were synthesized on a gold/glass substrate via spin coating. The films were annealed at a temperature between125∘Cand180∘C. Nanoscale characterisation of the morphology, polarization switching, and local piezoresponse hysteresis loops of PVDF-TrFE film was studied using a scanning probe microscope (SPM). Ferroelectric switchable domains were identified by piezoresponse force microscopy (PFM) for all films. Small grains, with weak piezoresponse character, were observed for films annealed just above the Curie temperature. Acicular grains were obtained when the annealing temperature approached the melting point and the piezoresponse increased. Annealing above the melting point decreased the piezoresponse and the morphology changed dramatically into plate-like structures.

scholarly journals SINTERING AND DURABILITY OF CLAYAND DIOPSIDE-CONTAINING CERAMIC AND FAIENCE WALL MATERIALS

2019 ◽  
pp. 122-133
Author(s):  
V. I. Vereshchagin ◽  
N. V. Mogilevskaya ◽  
T. V. Safonova
Keyword(s):  
Melting Point ◽  
Mineral Content ◽  
Annealing Temperature ◽  
Ceramic Materials ◽  
Simultaneous Increase ◽  
High Melting Point ◽  
Ceramic Mixture ◽  
Mechanical And Physical Properties ◽  
Ceramic Sintering ◽  
Wall Ceramic

The paper summarizes the research results of sintering and durability of wall ceramic materi-als modified by diopside-containing raw products and based on low-melting-point clays and loams, and kaolinand high-melting-point clay faience. Mechanical-and-physical properties of ceramic materials are identified and studied after annealing, depending on the diopside content. It is shown that depending on the content and introduction of clay minerals in the ceramic mixture, both coarse (0.5–1 mm) and fine (0.06 mm, dominating particle size of 0.01–0.015 mm) dis-persed diopside particles can be used. It is found that for loams with the clay mineral content of less than 10 wt.%, the addition of finely-dispersed diopside particles is more efficient. The latter provides ceramic sintering at 1000–1100 °С and increases its strength by 1.5–2 times. The intro-duction of dispersion diopside particles in the faience mixture lowers the annealing temperature from 1250 to 1150 °С with a simultaneous increase in its strength.  

Electron Beam Damage of Biomolecules Assessed by Energy Loss Spectroscopy

1978 ◽  
Vol 36 (3) ◽  
pp. 61-69
Author(s):  
M. Isaacson ◽  
M.L. Collins ◽  
M. Listvan
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Structural Integrity ◽  
Analytical Electron Microscopy ◽  
High Dose ◽  
Dose Rates ◽  
Special Cases ◽  
Analytical Electron ◽  
Atom Migration ◽  
Beam Damage

Over the past five years it has become evident that radiation damage provides the fundamental limit to the study of blomolecular structure by electron microscopy. In some special cases structural determinations at very low doses can be achieved through superposition techniques to study periodic (Unwin & Henderson, 1975) and nonperiodic (Saxton & Frank, 1977) specimens. In addition, protection methods such as glucose embedding (Unwin & Henderson, 1975) and maintenance of specimen hydration at low temperatures (Taylor & Glaeser, 1976) have also shown promise. Despite these successes, the basic nature of radiation damage in the electron microscope is far from clear. In general we cannot predict exactly how different structures will behave during electron Irradiation at high dose rates. Moreover, with the rapid rise of analytical electron microscopy over the last few years, nvicroscopists are becoming concerned with questions of compositional as well as structural integrity. It is important to measure changes in elemental composition arising from atom migration in or loss from the specimen as a result of electron bombardment.

Radiation Damage in Ceramics

1982 ◽  
Vol 40 ◽  
pp. 600-603
Author(s):  
T. E. Mitchell ◽  
M. R. Pascucci ◽  
R. A. Youngman
Keyword(s):  
Radiation Damage ◽  
Outer Space ◽  
Point Of View ◽  
Nuclear Waste Storage ◽  
Waste Storage ◽  
Storage Media ◽  
Transmission Electron ◽  
Fundamental Point ◽  
Small Defect ◽  
Present Understanding

1. Introduction. Studies of radiation damage in ceramics are of interest not only from a fundamental point of view but also because it is important to understand the behavior of ceramics in various practical radiation enyironments- fission and fusion reactors, nuclear waste storage media, ion-implantation devices, outer space, etc. A great deal of work has been done on the spectroscopy of point defects and small defect clusters in ceramics, but relatively little has been performed on defect agglomeration using transmission electron microscopy (TEM) in the same kind of detail that has been so successful in metals. This article will assess our present understanding of radiation damage in ceramics with illustrations using results obtained from the authors' work.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Review of the Radiation Damage Problem of Organic Specimens in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 476-477
Author(s):  
L. Reimer
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Irradiation Time ◽  
Dose Effect ◽  
Primary Process ◽  
Thin Specimen ◽  
Secondary Damage ◽  
Small Doses ◽  
Micro Organisms ◽  
Damage Processes

Most information about a specimen is obtained by elastic scattering of electrons, but one cannot avoid inelastic scattering and therefore radiation damage by ionisation as a primary process of damage. This damage is a dose effect, being proportional to the product of lectron current density j and the irradiation time t in Coul.cm−2 as long as there is a negligible heating of the specimen.Therefore one has to determine the dose needed to produce secondary damage processes, which can be measured quantitatively by a chemical or physical effect in the thin specimen. The survival of micro-organisms or the decrease of photoconductivity and cathodoluminescence are such effects needing very small doses (see table).

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