ISSN:0033-7579    

DOI:10.1080/00337578408217836

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A collision cascade involving transition and thermal stages is simulated by the molecular dynamics technique (MDT) in copper, the energy of the primary knocked-on atom (PKA) being 5 keV and 1 keV. At these stages an intense diffusion by interstitial and vacancy mechanisms occurs. Frenkel pairs are shown to be generated in appreciably larger amounts as compared to a proper cascade stage (by 4 to 5 times). Sufficient energy gradients within a cascade region (CR) lead to an increase in the average distance between the interstitials and the depleted zone, and also in vacancy concentration in the centre of the CR.

ISSN:0033-7579    

DOI:10.1080/00337578408217837

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

By the molecular dynamics technique (MDT) it is shown that in fcc metals vacancy type dislocation loops aligned preferentially with an external stress may occur within cascade regions (CRs) during a thermal spike. The influence of this process on radiation-induced creep is discussed.

ISSN:0033-7579    

DOI:10.1080/00337578408217838

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Radiation hardening caused in molybdenum by reactor neutron irradiation and 28-MeV alpha-particle bombardment is studied. 28-MeV alpha-particles are used as a model irradiation simulating CTR radiation effects. It is shown that at earlier stages of irradiation neutrons are more effective in the sense of hardening influence, but as the damage level increases, alpha-particles become the stronger hardening irradiation. It is concluded that radiation hardening of molybdenum is determined by defect structure in whose creation both low and high energy processes of radiation damage take place. PKA spectra are of great importance in the production of hardening defects.

ISSN:0033-7579    

DOI:10.1080/00337578408217839

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

When SrCb: Mn is irradiated at liquid nitrogen temperature Mn+defects are created. Their EPR spectrum consists of a six-sextet isotropic signal which can be explained using an isotropic spin-Hamiltonian with ag-value of 2,000±0.005 and hyperfine constant of 700±5 MHz. A superhyperfine structure due to the interaction with the eight surrounding Cl− ions can be also seen when the magnetic field is along the <100> directions. A model consisting of a Mn+ion in the center of a cube of chlorines is proposed for the Mn+defects.

ISSN:0033-7579    

DOI:10.1080/00337578408217840

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The disorder generated by 40-keV Si+implantation of (100) InP has been studied as a function of ion fiuence and flux density using the Rutherford backscattering-channelling technique. The effects of disorder production by the 2-MeV He+analysing beam on the implanted samples were minimal. The resulting disorder was, however, highly dependent upon flux density. Considerable annealing, which reduced the total disorder was found to take place during implantation, storage and during analysis.

ISSN:0033-7579    

DOI:10.1080/00337578408217841

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In the present work, applying the Thomas-Fermi-Firsov potential, the approximated formulae for calculations of elastic energy losses of heavy ions in solids were obtained. It is found that the elastic energy losses of low-energy atoms are not constants. With the increase of the ion energyEthe elastic loss grows, and at a definite energy maximal values are obtained. Under a further increase ofEthe elastic energy losses of the ions are slowly decreased. The energyEcorresponding to the maximum of the energy loss of an ion is increased with the increase of the atomic numbers of the colliding atoms (Z1, Z2). The elastic energy losses of the heavy ions were calculated in silicon.

ISSN:0033-7579    

DOI:10.1080/00337578408217842

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The influence of elastic and inelastic electron scattering as well as scattering in a plane on the line broadening of spontaneous planar-channeling radiation of electrons with an energy of 54 MeV in a diamond was analyzed.

ISSN:0033-7579    

DOI:10.1080/00337578408217843

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

3 MeV electron irradiations onMo57Co Mössbauer samples were performed with various fluences at 100 K irradiation temperature. Using the Mossbauer technique the trapping of interstitials, mobile at irradiation temperature, in different configurations around the 57Co impurities, could be directly observed from the appearance of additional absorption lines in the Mössbauer spectra. Analysing the irradiation dose dependent population of these defect lines, four different stable sites for trapped single interstitials and two di-interstitial sites were found. They are characterized by a nearly unique isomer shift of +0.46 mm/s relative to a substitutional lattice site and large quadrupole splittings ranging from 1.82 to 0.81 mm/s. At higher irradiation doses interstitial clustering at the 57Co impurities was found, resulting in a defect line with 0.39 mm/s quadrupole splitting and a broadened line width. The general trapping behaviour of theMo57Co system could be described by the unsaturable trap model with a trapping radius ofrco/rv= 0.23. The microscopic picture for the population of the observed trapping sites for interstitials is discussed within this model.

ISSN:0033-7579    

DOI:10.1080/00337578408217844

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Interplay between desorption, ordinary and electrical field assisted diffusion processes of alkali ions during Auger electron spectroscopy of dielectric solids has been quantitatively discussed. It is shown that the alkali Auger signal decay is mainly connected to alkali ion migration towards the interior of the electron irradiated-glasses. Comparison between many theoretical and experimental results clearly supports this physical idea which contrasts the point of view of a recently published work.

ISSN:0033-7579    

DOI:10.1080/00337578408217845

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor