Structural and optical properties of CR-39 polymer implanted with laser produced plasma ions of iron (original) (raw)
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Irradiation Effects of 40 – 250 keV Fe ions on Structural and Optical Properties of CR-39 Polymer
Materials Today: Proceedings, 2015
A passive Q-switched Nd:YAG pulsed laser was used to irradiate 99.99% pure Fe target in vacuum ~10-3 Torr. The CR-39 specimens were exposed to laser produced plasma ions (40-250 keV) emitted along the normal to the Fe target surface. The flux of Fe ions was varied by varying the number of laser shots in the range 500-1500 with an increment of 250. A comparison of structural and optical properties of CR-39 polymer before and after ion implantation was made. The increase in ion flux leads to the transformation of polymer into rather more disordered amorphous state leading to the broadening of XRD peaks. The crystallite size decreases (3.547 to 1.618 nm) and Urbach energy increases (0.232 to 0.291 eV) exponentially with the increase in ion flux (0 to 6.07 × 10 5 ions/cm 2). Indirect optical band gap is found to decrease (4.118 to 3.917 eV) linearly with the increase in ion flux (3.03×10 5 to 6.07×10 5 ions/cm 2).
The laser-produced plasma (LPP) ions of various metals (Mo, Ni, Cu, Ti and Zn) was implanted in CR-39 polymer, and their influence on its optical properties was investigated. The plasma of these metals was produced using 200 shots of a Q-switched Nd:YAG pulsed laser in a vacuum of 10 −3 Torr. The CR-39 specimens were exposed to LPP ions (flux: F = 8.01 × 10 9 − 22.14 × 10 9 ions/m 2 , average energy: E av = 52 − 297 keV) emitted along the normal to the metal surface in each case. Both F and E av were found to be a function of the room temperature Debye-Waller thermal parameter B and increase with increase in B-value. The structural behavior of virgin and implanted specimens was investigated using a ultra violet (UV)-visible spectrophotometer. The value of disorder content (Urbach energy E u ) was found to lie in the range of 0.287-0.377 eV. The optical band gap energy (E g ) for indirect transition decreased on implantation with metallic LPP ions, whereas such a variation in the case of direct transition was negligible. It was observed that E g for indirect transition increases with the increase in E u , whereas the dependence of E g for direct transition on E u was negligible.
Optical Behaviour of N[sup +] Ion Implanted CR-39 Polymer
2011
Polycarbonate samples were implanted with 100 keV N + ions at fluences 10 15 , 10 16 and 5 Â 10 16 ions cm À2 . Drastic alterations in UV-Visible transmittance spectra were observed which are interrelated with change in surface color and optical absorption of the implanted samples. UV-Visible transmission studies show that at ion fluence of 10 16 ions cm À2 , transmission approaches to zero at about k = 427 nm and below up to 200 nm. Optical band gap (E OPT ) reduces with increase in fluence and at maximum ion fluence of 5 Â 10 16 N + cm À2 , E OPT was determined to be 1.56 eV whereas for pristine its value was 3.00 eV. Raman analysis indicates the formation of amorphous carbon on the surface of polycarbonate at an ion fluence of 10 16 N + cm À2 . Rise in fluence to 5 Â 10 16 N + cm À2 results in enhancement in disorder on the surface of the host polymer. Modifications in the structural arrangements were found to be in strong association with changes in optical properties with increase in ion fluence and the same is discussed.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997
In this study we report hardness changes and structural effects in the polymer Cr-39 following implantation with 50-keV hydrogen and argon ions to doses between 1 X lOI and 2.8 X lOI ions/cm2. An increase in hardness (maximum contact pressure) was observed following both H and Ar implantation, with increases by factors of 6.5 and 1.5, respectively. Significant compaction of the ion beam modified layer was also observed for both ion species. These results suggest that the bonding changes induced by H implantation, which is dominated by electronic stopping processes, are more effective at enhancing the hardness of CR-39 than Ar implantation, which has considerable nuclear as well as electronic stopping.
the microstructural analysis of infrared irradiated CR-39 polymer
International Journal of Applied Mathematics and Computer Science
in order to obtain fundamental information on the modification of polymer due to irradiation, X-ray diffraction, FTIR (Fourier transform infrared) spectroscopy, UV-Visible spectral analysis, has been employed to CR-39 (Columbia Resin) polymer irradiated by IR (Infrared) radiations. the effect of infrared radiations on the physical, optical and chemical properties have been reported in this paper.
The effect of infrared laser on the activation energy of CR-39 polymeric detector
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012
The effect of infrared laser of wavelength (l¼ 1064 nm), pulse energy of 40 mJ/pulse at a repetition rate of 10 Hz, on the activation energy of CR-39 polymer, solid state nuclear track detector, has been investigated. Fifteen detectors were divided into three sets of equal numbers. The first set (un-exposed to laser beam), used as a reference set, was irradiated in close contact with an alpha source ( 241 Am). The second set (post-exposed) was first exposed to alpha radiation in close contact to the same 241 Am source and then treated in air with laser at energy intensity 8 J/cm 2 . For the third set (pre-exposed), the process was reversed (laserþ alpha) under the same conditions. The activation energies of bulk etch (E B ) for unexposed, post-exposed and pre-exposed are found to be equal to 0.98, 0.91, and 1.0 eV, respectively. The respective activation energies of track etch (E T ) for unexposed, post-exposed and pre-exposed are found to be equal to 0.71, 0.75, and 0.97 eV.
A comparative study of the effect of O+ 7ion beam on polypyrrole and CR-39 (DOP) polymers
Journal of Physics D: …, 2008
Polypyrrole thin films doped with para-toluene sulphonic acid were prepared by the electrochemical process. High-energy ion beam irradiation of the polymers is an effective technique to enhance the electrical conductivity, structural property and mechanical properties. So polypyrrole and allyl diglycol carbonate (CR-39 (DOP)) films were irradiated by oxygen ions (energy 100 MeV, charge state O +7 ) with fluence varying from 1 × 10 10 to 1 × 10 13 ions cm −2 . The effects of swift heavy ions (SHI) on the structural, optical and surface properties of polypyrrole (Ppy) and CR-39 (DOP) polymers were studied in this work using x-ray diffraction (XRD), UV-visible spectroscopy and scanning electron microscopy (SEM). XRD patterns of the pristine and irradiated polymer show that the crystallinity improved after the irradiation with SHI. At the low fluence, crystallinity was found to increase but at high fluence, it decreases which could be attributed to cross-linking and degradation mechanism. The UV-visible spectra show a shift in the absorbance edge towards higher wavelength, which can be correlated with the transition involved in the polymer and variation in the band gap using Tauc's expression. The band gap of polypyrrole was found to decrease from 3.4 to 3.0 eV after irradiation. CR-39 (DOP), however, showed a very large change in the band gap from 4.8 to 3.4 eV. The SEM study shows a systematic change in the surface morphology of the polymers with increasing ion fluence.
Ion beam modification of surface properties of CR39
Philosophical Magazine, 2010
Improvement of polymer tribological properties is an essential issue for their application when used as parts of machines or artificial human joints. Ion implantation is a very promising technique in this respect. This paper presents the application of energetic He and Ar ions for this purpose. The materials studied were low-density (LDPE) and highdensity (HDPE) polyethylene and their blends. Atomic force and scanning electron microscopes were used for studies of surface modifications. Tribological tests consisted of friction coefficient and nanohardness measurements. Our results have indicated clearly that ion bombardment produces important changes in the polymer surface morphology and its internal structure. The related micromechanical parameters strongly depend on polymer density. For the pristine samples, the friction coefficient increases with decreasing polymer density. For hardness, opposite tendency was observed. A significant increase of hardness and friction coefficient was observed for HDPE subjected to ion bombardment. In contrast, ion bombardment does not produce significant changes of tribological parameters in 50-50 blend and LDPE. r