摘要:

When resonant nuclear reactions are used for hydrogen analysis of solid materials, under beam impact a systematic variation of surface hydrogen content is observed as a function of the ion fluence, leading to a dynamic equilibrium value.

ISSN:0033-7579    

DOI:10.1080/00337578208229934

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A heterogeneous interstitial nucleation model for the radiation-inducedF-coloring in alkali halides is here presented. It applies to the temperature region whereHcenters are mobile, although comparison with ex periments is primarily restricted to the behavior near room temperature. The model assumes the creation ofFandHpairs as the primary event, as well as secondary thermally-activated interstitial processes. These include recombination withFcenters as well as capture by empty traps (very likely impurities) and by all clusters formed after successive interstitial trapping. Therefore, a heterogeneous nucleation model is assumed for the interstitial-aggregation. As the key point of the model it is proposed that one of the interstitial centers (that containing two trapped interstitials) formed in the process of clustering is highly unstable.

ISSN:0033-7579    

DOI:10.1080/00337578208229935

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The essential features of a Monte Carlo program which simulates the scattering and the retardation of energetic ions in amorphous targets are presented. The new experimentally derived universal scattering cross-section of Kalbitzer and Oetzmann is used to describe nuclear scattering events. For electronic energy loss, the Lindhard-Scharff and Bethe formulae are used. The program was primarily developed to study the spatial distribution of ion deposited energy for lithographic applications. However, for initial verification, the program has been used to study the fundamental characteristics of ion transport for various ion-target combinations. The theoretical predictions obtained using the above expressions for nuclear scattering and electronic energy loss are shown to agree very well with experimental results.

ISSN:0033-7579    

DOI:10.1080/00337578208229936

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

SiOxlayers with continuous depth profiles of the oxygen concentration are formed about 2 μ below the surface by 2 MeV Si ion implantation into fused silica. The depth distribution of the changed optical properties is revealed by high-resolution reflection and transmission profiles measured across the beveled surface of the irradiated samples. The underlying depth profiles of the refractive index and of the extinction coefficient are evaluated from reflection and transmission measurements by a method which is based on exact formulas for the light propagation within continuous depth profiles of the complex refractive index. The resultingnandkprofiles are correlated with depth profiles of the oxygen concentration which are theoretically calculated for the investigated dose range (1 × 1016to 6 × 1017cm−2). The optical data of SiOxforxbetween 2 and 1.1 are presented in the wavelength range from 365 to 1000 nm. Comparison with the effective medium model proposed by Zuther for evaporated SiOxand with experimental data of evaporated layers shows the influence of bonding defects on the optical properties of ion implanted SiOx.

ISSN:0033-7579    

DOI:10.1080/00337578208229937

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Based on the binary collision approximation, computer simulation has been performed in order to investigate the dependence of ion reflection coefficient and energy spectrum of reflected ions on the azimuthal angle of incidence near the semichannel direction. Pronounced azimuthal dependences of the total reflection coefficient and the energy spectrum are found, especially when the incident energy is equal to the focusing energy of the surface semichanneling.

ISSN:0033-7579    

DOI:10.1080/00337578208229938

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor