摘要:

This paper is a review of experimental, theoretical and computer studies of the ejection of fast recoil atoms from solids under ion bombardment.

ISSN:1042-0150    

DOI:10.1080/10420158908212967

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A quantitative description of the breaking of a bond between two ions is given by the Landau-Zener-Stueckelberg (LZS) model. In this paper, the possible application of this model to the metallic positive emission is discussed. The example of Cu+emission is chosen in order to show that the model alone is unable to describe the whole ionization processes, and that it has to be inserted into a more comprehensive description. The bond breaking could for instance follow the promotion of a bound electron, or it could occur between the emitted cation and a complex anion including oxygen. Both possibilites can take into acccount the “matrix effect” observed in alloy sputtering.

ISSN:1042-0150    

DOI:10.1080/10420158908212968

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effects of Ar bombrdment on carbonitrides produced by N implantation in a low carbon steel are studied by Conversion Electron Mössbauer Spectroscopy. The results show two main features: dissolution and reprecipitation of the produced carbonitrides and modification of the thermal behaviour of the precipitates. Recently we have performed similar experiments bombarding samples of the same steel with He. The comparison of both experiments shows that the Ar post-bombardment is not only more effective in the dissolution and reprecipitation process, but also is more efficient in the carbonitride retention at 450°C.

ISSN:1042-0150    

DOI:10.1080/10420158908212969

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The thermoluminescence (TL) glow curves ofγ-irradiated magnesium phosphate glass sample have been studied for dosimetric purpose in the dose range from 2.5 to 120 Gy. The resulted glow curves have exhibited two peaks whose positions were dependent on heating rate. The intensity of the glow peaks was found to be dose dependent. The dose calibration curves of the prepared glass specimen have shown a reasonable linearity behaviour over the studied dose range. Results of the present invetigation reflected the usability of such glass samples asγ-ray dosimeter up to a dose of 120 Gy.

ISSN:1042-0150    

DOI:10.1080/10420158908212970

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A Monte Carlo calculation for the energy spectra of electrons and positrons produced in infinite and semiinfinite water phantoms by photons ranging in energies from 20 keV to 1 GeV are presented. The dominant processes considered are the photoelectric effect, Auger effect, Compton effect, pair, and triplet production. Bremsstrahlung produced by electrons and positrons with energies greater than 1 MeV is also included. The effect of multiple Compton scattering, not considered in the earlier calculation, for the infinite phantom for photon energies higher than 2 MeV has been incorporated. For a semi-infinite phantom, multiple Compton scattering and backscattering through the top are considered. The results are compared with the earlier calculations for the first-collision spectrum. It is found that the inclusion of multiple Compton scattering significantly increases the average number of electrons/cm3per photon/cm2at all energies considered whereas bremsstrahlung reduces the number of high energy electrons and produces more low energy electrons in the spectrum.

ISSN:1042-0150    

DOI:10.1080/10420158908212971

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

X-ray investigations of Bragg scattering measurements have been carried out on the dilute solid solutions of AgxNa1−xCl forx= 0.03 and 0.10. The integrated intensities are measured on spherical single crystals, using a home-built manual X-ray diffractometer. The analysis of experimental data indicates an enhancement of Debye-Waller factor in this system. The size effect distortion factors evaluated are compared with the calculated values on the basis of different theoretical models and the results are discussed. The measured cell constant and density data indicate the existence of vacancies in these crystals.

ISSN:1042-0150    

DOI:10.1080/10420158908212972

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Magnetic After-Effect isotherms have been measured on a metallic glass pre-annealed for different times. The results have been analyzed simultaneously by Debye relaxation functions leading to spectra of activation enthalpies and by extended exponential functions leading to a unique effective activation enthalpy. The thermodynamic activation parameters issued from both analyses compare well. The average values of the enthalpy spectra determined by assuming Debye relaxations are equal to the effective enthalpies resulting from the non-Debye relaxation.

ISSN:1042-0150    

DOI:10.1080/10420158908212973

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An EPR study of Mn2+ions doped in single crystals of Dihydrate Magnesium Maleate has been carried out at room temperature at X-band. From the observed spectra, spin-Hamiltonian parameters have been evaluated. Mn2+ions have been found to enter the lattice interstitially.

ISSN:1042-0150    

DOI:10.1080/10420158908212974

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor