摘要:

Soda-lime glasses have been irradiated by using different ions (H, N, O, Ne, Ar, Kr) in 20–300 keV energy range. The observed modifications in the alkali depth distribution have been analyzed on the basis of a phenomenological model, which takes into account for an enhanced diffusion and a surface preferential sputtering. A correlation between the alkali sputtering cross-section and the electronic stopping power regimes of incident particles has been determined. The alkali profiles, before and after irradiation, have been determined by resonant nuclear reactions.

ISSN:0033-7579    

DOI:10.1080/00337578608206102

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The bombardment of a glass target by an electron beam has been used to investigate charge propagation in a dielectric medium. A model is described for complex impedance determination. The results are compared with experimental data obtained at room temperature by a capacitance bridge. The validity of the simplified theory of electron and ion propagation which accounts well for variations with electron beam energy is discussed and it appears that measurements by comparison with a standard specimen permits one to ignore the exact value of some parameters whose variation with initial conditions are not known with sufficient accuracy.

ISSN:0033-7579    

DOI:10.1080/00337578608206103

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Ion bombardment of organic materials produces dramatic changes in their properties associated with disruption and rearrangement of the original chemical bonding and formation of new molecular products. In polymers, bombardment results in cross linking and/or chain scission, gas evolution and eventual carbonization. In films of relatively non-volatile organic molecules ion bombardment can result in polymerization or in decomposition with metallic residue film formation. Intense laser radiation in polymers can lead to material ablation through explosive ejection processes. Similar explosive effects are implied by the results of ion beam irradiation of nitrocellulose. The status of the field of ion bombardment effects in organic materials is still in its infancy from the point of view of detailed understanding of the mechanisms involved. This article is a brief review of the diversity of effects being studied.

ISSN:0033-7579    

DOI:10.1080/00337578608206104

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

We report the first results of ion-beam-induced polymerization of a diacetylene. Large area (≃ 0.5 × 0.5 cm) thin (≃ 1 μm) single crystal TCDU (bis-phenylurethane of 5,7-dodecadiyn-1,12-diol) monomer films have been obtained using a novel melt-shear growth technique. The solid state polymerization reaction of these films was initiated by ion beams in 100 keV energy range. Raman spectroscopy and optical absorption experiments have been performed to characterize the polymerized crystalline samples. The quality of the polymeric films has been studied as a function of the ion beam energy and fluence of implantation. Highly anisotropic films of good quality were obtained using very low implantation fluences ( < 1013cm−2) and ion beam currents during the irradiation. Our data shows that the polymeric film thickness can be well controlled by the ion beam parameters. Results of ion beam and UV irradiation induced polymerization are compared.

ISSN:0033-7579    

DOI:10.1080/00337578608206105

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) samples have been irradiated with X-rays, electrons and energetic heavy ions. Changes of electronic structure and chemical bonding have been studied by X-ray photoelectron spectroscopy (XPS).

ISSN:0033-7579    

DOI:10.1080/00337578608206106

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Ar+beams of 1.5 MeV energy have been used to produce highly conducting films from the previously insulating photoresist HPR-204. Typical recuctions are from 1012Ωcm to 10−2Ωcm. When utilising a beam of an inert gas such as Ar, the choice of beam energy coupled with film thickness is critical because a significant amount of Ar is stopped in the polymer film and agglomerates causing blistering and peeling of the film, confirmed by micrographic evidence and measurement of film thickness which indicate competition between component loss and gas incorporation processes. This also causes the films to be very sensitive to subsequent temperature treatment.

ISSN:0033-7579    

DOI:10.1080/00337578608206107

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The chemical phenomenology which occurs in polystyrene films bombarded with low doses 100 keV He+ions has been investigated by infrared spectroscopy. The results obtained show that the polymer is rapidly transformed into a different chemical compound consistent with high cross-linking as indicated by low solubility in CHCI3. The I.R. finding is in agreement with XPS findings and indicates that the observed phenomenology occurs via a mechanism which eliminates the electronic “π” system of the phenyl ring and gives rise to alkene-type bonding.

ISSN:0033-7579    

DOI:10.1080/00337578608206108

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Samples of high-purity low-density polyethylene (LDPE) film were irradiated to doses in the range 0 to 104Gy in a60Co gamma source. Following irradiation, the charging current for applied fields up to 1.3 × 108V m−1and the subsequent short-circuit discharging current were each monitored for 10 min. Finally the dielectric breakdown strength was determined upon the application of a 10 kV/μs voltage ramp. The samples were maintained at 5 K throughout the irradiation and the electrical measurements. The results show that60Co gamma radiation has no significant effect on either the conductivity or dielectric breakdown strength of LDPE at 5 K for doses up to 104Gy. The measurements also suggest that the dominant charge transport process observed in the present work is due to some form of polarisation.

ISSN:0033-7579    

DOI:10.1080/00337578608206109

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Parameters of relevance to ion beam lithography and ion implantation masking have been determined for two polymer resists, PMMA and Microposit 23M. These have been bombarded with 50 keV As+at low power densities in order to avoid blister formation. Loss of volatiles was found to cease and lateral stress (in PMMA) changes from tension to compression at a critical dose of 1015ions cm−2. These parameters were measured using a triple quartz resonator technique (TRT). X-ray photoelectron spectroscopy (XPS) data indicate a loss of oxygen in the bombarded resists by reduction of −C=O groups. The arsenic concentration, measured by Rutherford Backscattering (RBS), rose linearly with As+ion dose with 100% retention of As+in the resists. A dose of 2 × 1012ions cm−2was required for full exposure of PMMA and the developed step height was found to correlate well with calculated arsenic range data.

ISSN:0033-7579    

DOI:10.1080/00337578608206110

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Ion irradiation can be used to modify the physical properties of optoelectronic materials in well defined regions and consequently, to produce integrated circuits in surface layers. In most cases, the change of physical properties such as the refractive index, the absorption coefficient, the density and the conductivity are strongly influenced by the radiation damage which is caused by the ion implantation process. So, the study of the generation, transformation and annealing of radiation defects as their connection with the physical properties of the materials is very important. A review of the effect of radiation damage on the properties of essential optoelectronic materials as SiO2and LiNbO3will be given in this paper. It deals mainly with the mechanism of defect generation, the annealing of defects by thermal treatment and the optical properties of materials affected with defects.

ISSN:0033-7579    

DOI:10.1080/00337578608206111

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor