摘要:

The amorphization process of GaP by ion implantation is studied. The samples of ⟨111⟩ oriented GaP were implanted at 130 K with various doses 5 × 1013-2 × 1016cm−2of 150 keV N+ions and with the doses of 6 × 1012-1.5 × 1015cm−2of 150 keV Cd+ions. Room temperature implantations were also performed to see the influence of temperature on defect production. Rutherford backscattering and channelling techniques were used to determine damage in crystals. The damage distributions calculated from the RBS spectra have been compared with the results of Monte-Carlo simulation of the defect creation.

ISSN:1042-0150    

DOI:10.1080/10420159008220569

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Studies concerning track shapes, etching characteristics and track density due to spontaneous fission of uranium along various crystallographic planes of apatite are represented. The studies were carried out on large complete crystals as well as on small grains of apatite belonging to various geological origins. Three track types (hexagonal, pyramidal and needle type) have been identified along various crystallographic planes.

ISSN:1042-0150    

DOI:10.1080/10420159008220570

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

On the basis of experimental results obtained in the present and some other works a model of melting of rare gas solids within bubbles formed in a crystalline metal matrix as a result of ion implantation is proposed. Rare gas solid is supposed to melt on heating at the expense of the bubble volume expansion by emission of a dislocation loop. On this basis the melting temperature can be estimated as one which is enough to provide for a pressure inside a bubble sufficient for the initiation of the dislocation loop punching. Values of melting temperatures obtained in this way are in good agreement with available experimental data.

ISSN:1042-0150    

DOI:10.1080/10420159008220571

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Crystal potentials have been derived for SrCl2and Na2S by first calculating the pair-interactions of the ions in the electron-gas approximation and then refitting the most crucial parameters to crystal properties. For both these materials it seems to be impossible to obtain a perfect description of crystal properties using current two-body interactions, so various compromise potentials have been studied that emphasize the fit to particular properties at the expense of others. Defect calculations with these potentials lead to some conclusions about the effect of weighting the fitting of certain properties (elastic constants, dielectric constants, phonon frequencies) but this is a field not much explored hitherto and so it is not known how general these conclusions might be. All the potentials confirm that the primary defects are anion Frenkel defects in SrCl2and cation Frenkel defects in Na2S. Calculated activation energies for defect migration appear to be on the low side, except for S2-migration in Na2S for which the experimental Arrhenius energy is unusually small. Some properties of defects in NaCl:S2-are discussed in the Appendix.

ISSN:1042-0150    

DOI:10.1080/10420159008220572

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor