Electron irradiation effects

Smith, B. W. and Luzzi, D. E. 2001. Electron irradiation effects in single wall carbon nanotubes. Journal of... 

Leon, R., Nadeau, J., Evans, K., Paskove, T., and Monemar, B. (2004) Electron irradiation effects on nanocrystal quantum dots used in bio-sensing applications. IEEE Trans. Nucl. Sci. 51, 3186-3192. 

Alexander D E, Rehn L E, Farrell K and Stoller R E (1996), Gamma-ray (electron) irradiation effects on tensile properties of ferritic alloys , / Nucl Mater, 228, 68-76. 

The NMR techniques were also used to analyze different structural, surface reactions, reaction mechanisms, and other aspects related to the surface chemistry of silicas. For instance. Brunet et al. (2008) studied the electron irradiation effects on controlled-pore borosilicate glasses (CPGs at 8 and 50 nm in pore size, 96% Si02 and 3% B2O3) using multinuclear solid-state NMR technique. H MAS NMR was used to study the surface proton sites. They showed that the irradiation leads to a dehydration of the material. The observed variation of the Q4, Q3, and Q2 species from H- Si CPM AS spectra showed an increase of the surface polymerization under irradiation, implying in majority a Q2 to Q3/Q4 conversion mechanism, and CPMAS measurements exhibited an increase in... 

Figure 21 Electron irradiation effects on the carrier density n and the Hall mobility (i, at room temperature for 3C-SiC and Si. no and Po indicate the carrier density and the mobility before irradiation, respectively. (From Ref. 121.)...

H Itoh, M Yoshikawa, I Nashiyama, S Misawa, H Okumura, S Yoshida. Electron irradiation effects on CVD-grown 3C-SiC epUayers. Springer Proceedings in Physics 56, Amorphous and Crystalline SUicon Carbide HI, 1992, p 143. 

High-resolution transmission electron microscopy (HREM) is the technique best suited for the structural characterization of nanometer-sized graphitic particles. In-situ processing of fullerene-related structures may be performed, and it has been shown that carbonaceous materials transform themselves into quasi-spherical onion-like graphitic particles under the effect of intense electron irradiation[l 1],... 

Fig. 3. Schematic illustration of the growth process of a graphitic particle (a)-(d) polyhedral particle formed on the electric arc (d)-(h) transformation of a polyhedral particle into a quasi-spherical onion-like particle under the effect of high-energy electron irradiation in (f) the particle collapses and eliminates the inner empty space[25j. In both schemes, the formation of graphite layers begins at the surface and progresses towards the center.

Fig. 17. LHeT absorption of the Si-related LVMs in p+-GaAs Si after holes capture by (a) electron irradiation-induced effects and (b) deuterium-related neutralizing complexes. The spectral resolution is 0.1 cm1. J. Chevallier el al., Mat. Res. Soc. Symp. Proc. 104, 337 (1988). Materials Research Society. 

Table II shows the effect of various doses of electron irradiation on the solubility of ethylene-ethylacrylate copolymer. Extraction with boiling toluene for 64 hours revealed extensive crosslinking after absorption of a 5-megarep dose of radiation. Copolymers of ethylene with isobutyl acrylate and 2-ethylhexyl acrylate were examined briefly. A 29 wt.% isobutyl acrylate-ethylene copolymer of melt index 1.3 decigrams per minute was crosslinked to greater than 50% insolubility in boiling toluene by a radiation dose of 10 megareps. A copolymer containing 21% by weight of 2-ethylhexyl acrylate of melt index 8 decigrams per minute required a dose of 25 megareps to reach a 50% level of insolubility.

Creep rates of three glassy polymers are much greater during electron irradiation than before or after. Radiation heating is eliminated as a possible cause. Essentially the same concentration of unpaired electrons and ratio of cross-linking to scission were found in polystyrene samples in the presence or absence of stress. The effects of radiation intensity, stress, and temperature on creep during irradiation are examined. The accelerated creep under stress is directly related to a radiation-induced expansion in the absence of stress. This radiation expansion is decreased by increase in temperature or plasticizer content and decrease in sample thickness. It is concluded that gas accumulation within the sample during irradiation causes both the expansion under no stress and the acceleration of creep under stress. 

The effects of electron irradiation on the properties of EPDM along with the optimization of PTFE loading for desired properties have been investigated. For preliminary investigations, PTFE powder L100X was modified with irradiation doses of 20, 100, and 500 kGy and then incorporated into EPDM at loadings of... 

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