摘要:

This part of the work completes the discussion of the results of computer simulation of Cu single-crystal and polycrystal sputtering by 27-keV Ar ions. Sputtering due to <110> linear collision chains is investigated here in detail. The effects of thermal vibrations and simultaneous collisions (lens focusing) on the parameters of the <110> collision chains are discussed. The energy spectra of atoms sputtered by the <110> collision chains of various types and the data concerning the initial formation stage of the <110> collision chains are presented. The characteristic energies in the spectra of atoms sputtered by pure focused and mixed (focused-defocused) collision chains have been shown to be different. Collision chains along an isolated Cu <110> atomic row are calculated as a subsidiary problem. The ranges of initial angles and energies pertaining to various types of collision chains have been found. The hard-sphere approximation and the many-body integration method were also used in some of the calculations for the sake of comparison. The angular dependence of the single-crystal sputtering yield studied in Part 1 of the work is discussed again in the light of new experimental data.

ISSN:0033-7579    

DOI:10.1080/00337578508218430

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The correspondence between observed and expected impurity distributions occurring in high dose, high temperature ion implantation, has been investigated for 60 keV Cu+ ions in poly-crystalline Ti. The expected atomic profiles are caclulated assuming a simple sputtering model of retention, and the actual profiles were determined by ion backscattering analysis. Implantation carried out at elevated temperatures (∼500–600°C) and to high doses (≳ 5.0 1016 ions/cm2) resulted in a marked redistribution of stopped material, with the Cu accumulating to form a peak well beyond the region of energy deposition. The magnitude and position of this deeper peak were found to be strongly dependent on the incident dose and target temperature, but only weakly dependent on dose rate and irradiation time. Further, in the early stages of its development (l∼2.0 1017 ions/cm2, 500°C) this anomalous peak propagated into the bulk without any significant broadening and by a mechanism which caused its position to depend linearly on the incident dose. The formation and subsequent migration of a solute-defect complex down its own defect concentration gradient is proposed as the most probable mechanism responsible for the observed redistribution.

ISSN:0033-7579    

DOI:10.1080/00337578508218431

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The dependence on the angle of incidence θ of the number-backscattering coefficientRnand the energy-backscattering coefficientReof H, D and He ions has been found to be fitted by the expressionR(θ)=R(0°) + [1-R(0°)]/(1 +A1 cot2A2θ), whereRrepresents eitherRnorREand the parametersAt(i = 1,2) are functions only of the Thomas-Fermi reduced energy ε. By using the semiempirical formulas of Tabataet al. forR(0°), universal formulas forR(θ) have been obtained These formulas are valid for all the mass regions of the target atom and for 2 × 10–2 ≲ ε ≲ 10.

ISSN:0033-7579    

DOI:10.1080/00337578508218432

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The electrical resistivity of an α-CuZn alloy containing 30 at.% Zn has been measured on-line during 3 MeV electron irradiation at temperatures between 299 K and 435 K. Negative resistivity changes due to short range ordering have been observed. For temperatures above 350 K stationary resistivity values, i.e. equilibrium states of short range order were achieved, which show a linear dependence on temperature. The relaxation rates which were determined from the resistivity kinetics are compared to those from resistivity and Zener relaxation experiments in the literature as well as to model calculations of the defect concentrations.

ISSN:0033-7579    

DOI:10.1080/00337578508218433

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

GaP crystals were irradiated uniformly on their flat surfaces by 10 MeV-electrons. The “below-gap” absorption coefficient δαb(hv) and the normalized white-light optical densityD/din these samples increased linearly with a dose φ as δαb(2.0) = 3.3 × 10–16 φ andD/d= 1.42 × 10–16φ. The free electron densitynin the conduction band estimated from the X1→X3 absorption band decreased with φ, and as the decrease in the free electron density δnis equivalent to the density of introduced defectsNit could be expressed thatN=δn =Rcφ where the value of the carrier removal rateRc was 5.8 cm-1 for the S-doped sample. These expressions lead to the basic relation thatNis proportional toD/das expressed inN=4.1 × 1016D/d.

ISSN:0033-7579    

DOI:10.1080/00337578508218434

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The proportional relations between the normalized white-light optical density D/d and an electron dose, andD/dand the damage density in the electron irradiated GaP crystal were obtained in the preceding paper.

ISSN:0033-7579    

DOI:10.1080/00337578508218435

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Single crystals of silicon were irradiated with neutron doses ranging from 2.5 × 1018 n cm-2 up to 2.5 × 1019 n cm-2 (E>0.1 MeV). Diffuse X-ray scattering from the irradiated and isochronal annealed samples was measured near the (440) reflection. There are two distinct annealing stages, one at 200°C and another at 600°C. From the variation of the size and the shape of the interstitial and vacancy clusters we identify the mobile defects. We conclude that at 200°C the divacancy is migrating while at 600°C interstitials are mobile. Thereby, single interstitials being evaporated is more likely than complete interstitial clusters becoming mobile.

ISSN:0033-7579    

DOI:10.1080/00337578508218436

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Frenkel-defect resistivity (ρf) ratios for pairs of metallic elements are estimated from published resistivity damage-rate data, obtained during low-temperature neutron irradiations. These ratios are used in order to determine the range of mutually compatible ρf values for the elements: Al, α-Co, Cu, Mo, Nb, Ni, Pt, Ta, α-Zr, in which ρF had been experimentally measured, and to estimate ρF values for Ag, Au, Cd, α-Fe, Pd, βSn, V, W. Among the proposed empirical relationships, the best correlation is obtained between ρF and the resistivity at the melting point.

ISSN:0033-7579    

DOI:10.1080/00337578508218437

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

With two techniques the defect complexes are studied when formed after implantation of 5 to 100 keV metal ions into tungsten. Perturbed Angular Correlation (PAC) studies clearly indicate the presence of substitutional impurities in samples implanted with Ag or In. With Thermal Helium Desorption Spectrometry (THDS), however, virtually no substitutional implants (Ag, Cu, Mn, Cr, In) could be seen after implantation due to the nearby vacancies. Migration of vacancies towards the implants during annealing at stage III temperature was observed by means of PAC measurements. At upper stage III vacancy-implant complexes disintegrate, while the substitutional fraction increases. According to THDS, no vacancy-implant complexes are left in the case of 5 keV implantation after annealing to temperatures slightly beyond stage III temperature. In the case of 20 keV implantation a vacancy-type defect is formed which is stable up to 1350 K. The results of both techniques are compared with each other and with model calculations.

ISSN:0033-7579    

DOI:10.1080/00337578508218438

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

LASER SPECTROSCOPY VI, H. P. Weber and W. Lüthy (Eds.), Springer-Verlag, Berlin, Heidelberg, 1983, pp. 442; $A 31.50.

ISSN:0033-7579    

DOI:10.1080/00337578508218439

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor