摘要:

Based on the radiation cascade theory, the recoil yield has been calculated for different ion-film combinations often encountered in practice. Also, the recoil yield has been found as a function of film thickness and depth distribution or recoiling atoms in graphite. Then, by the Rutherford backscattering method the recoil yield and the depth of penetration of recoiling atoms in glassy carbon were determined experimentally. The parameters so found were compared with the theoretical data. Thereafter, the adhesion strength of tin, silver and molybdenum films on the surface of carbon materials was determined by the scratch test method, after the implantation of Ar+ions (100 keV). An appreciable increase in the adhesion strength of these films was noticed. A relationship has been established between the increase in adhesion strength and the irradiation dose. The films of the used metals (tin and silver) which do not react chemically with carbon enabled us to explain the cause of increase in the adhesion strength. This increase is caused not by chemical bonding but by radiation enhanced mixing of the metal and carbon atoms.

ISSN:1042-0150    

DOI:10.1080/10420159108221339

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Yields and energy spectra of neutral and charged particles sputtered from Cu target under 5.5 keV Ar+ion bombardment have been measured. The yield of Cunneutrals falls off rapidly with increasingnthat can be explained by the recombination model. The yield of Cun+ions depends unmonotonously onn.The ionization probability of sputtered particles is described by an exponential dependence exp[-(In- ϕ)/ε0], whereInis the ionization potential of Cuncluster, ϕ is the work function and ε0is a parameter.

ISSN:1042-0150    

DOI:10.1080/10420159108221340

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A general interatomic potential is given, which is based on a new combination rule for the screening length. It depends only on the atomic numbers of collision partners. It is compared to accurate potentials. In cases of K+→ W and Ar+→ Cu collisions this potential is very close to the accurate potentials determined theoretically and experimentally. In addition the generality of this potential is examined, particularly for the low energy part, in terms of the correction factors to the screening length for various cases of atomic number combinations. This potential yields a good fit to individual experimental results. These facts support the reliability of this potential and the new combination rule for the screening length as its basis.

ISSN:1042-0150    

DOI:10.1080/10420159108221341

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Polymers play an increasing role in technical applications. Presently the polymer polymethylmethacrylate (PMMA) has been found to be a suitable materials for the fabrication of optical devices, where the refractive index can be altered considerably by ion bombardment. Drastic increases of the refractive index have been observed after ion implantation at doses of the order of 1014/cm2. The dependence of the refractive index on ion energy, ion dose and ion species was investigated for H+, He+, N+, N2+, C+, O+, F+, Si+, Ar+, Zn+, Kr+, and Xe+at energies ranging from 100 keV to 350 keV for ion fluences between 1013/cm2and 4 × 1014/cm2. The radiation sensitivity and the attainable changes of the refractive index in PMMA were found to exceed drastically any previously known value. Therefore, this material may be judged to become suitable for many kinds of future micro-optical applications.

ISSN:1042-0150    

DOI:10.1080/10420159108221342

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Monte Carlo calculations have been carried out for the sputtering energy reflection coefficient (YE) of plasma ions incident on a carbon surface. The calculations incorporate a simulation of the velocity distribution of plasma ions incident on a surface with a floating potential. The average energy of an ion can increase by more than a factor of three as a result of this potential and the effect onYEcan be significant. An analytic form forYEis constructed expressed in terms of the ion plasma temperature and the surface floating potential. The new model provides a fast and accurate means to calcualteYE.

ISSN:1042-0150    

DOI:10.1080/10420159108221343

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Ion implantation at plasma-facing surfaces is affected by the formation of the electrostatic sheath potential. The average energy of an ion can increase by more than a factor of three as a result of the sheath and the effect on ion implantation can be significant. In this paper, Monte Carlo calculations of plasma ion implantation are carried out including the effect of the sheath. The calculations incorporate a simulation of the velocity distribution of plasma ions incident on a surface with a floating potential. The effect of the surface floating potential is included in a new analytic model for plasma implantation. The new model should provide a fast and accurate means to calculate the distribution of plasma ion implantation.

ISSN:1042-0150    

DOI:10.1080/10420159108221344

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Magnetic garnet Y3Fe5O12and magnetic ferrite BaFe12O19have been irradiated at room temperature by Kr and Xe ions using the GANIL accelerator at Caen and by U ions using the Unilac accelerator at Darmstadt. These experiments allow to cover a wide range of electronic stopping power values (between 7 MeV/μm and 45 MeV/μm) using the ion beam at energy between 40 MeV/a.m.u. and 8 MeV/a.m.u. Transmission Mössbauer spectrometry has been used to determine the damage cross section A for the corresponding value of electronic stopping power. High resolution electron microscopy observations confirm the A determination for the highest value of dE/dx. The main feature is the appearance of a saturation in the damage efficiency ϵ =A/dE/dxabove an electronic stoping power valueTM. Using all the previous results, damage evolution and damage morphology description will be proposed and comparison with the chemical etching sensitivity of the magnetic garnet will be done.

ISSN:1042-0150    

DOI:10.1080/10420159108221345

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

High substitutional fractions,fs, with values up to 0.87 were measured for Au implanted into Al single crystals at 77 K with peak concentrations up to 5 at.%. This solubility limit exceeds that observed for 293 K implants by one order of magnitude. At higher Au concentrations a transformation takes place most probably into an amorphous phase. Annealing the 77K implants at 293 K leads to a decrease infs. Postirradiation experiments with 300 KeV He and Ar ions at 77 K suggest that the decrease offsupon annealing is maily due to Au precipitate formation.

ISSN:1042-0150    

DOI:10.1080/10420159108221346

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Ar ion radiation produced defects in ZnTe crystals and their annealing are investigated using transmission electron microscopy. The defects are identified to be densely distributed small dislocation loops. Under electron beam irradiation, these dislocation loops are seen to reduced in density considerably. This electron beam induced defect annealing is explained qualitatively in terms of the non-radiative recombination of excited electron on the defects.

ISSN:1042-0150    

DOI:10.1080/10420159108221347

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Powder samples of57Fe2O3,56Fe2O3and hematite of natural isotope abundance implanted with54Fe,56Fe and57Fe ions were studied using Conversion Electron Mössbauer Spectroscopy. The formation and thermal stability of Fe3O4and FeO precipitates were investigated. The observed fractions of each state of iron agree well with the calculated values obtained from the iron concentration profile as well as from the analysis of the equilibrium phase diagram for the binary Fe-O system. Possible differences in local states of implanted ions and of those displaced from the substitutional positions in the target are discussed.

ISSN:1042-0150    

DOI:10.1080/10420159108221348

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor