摘要:

A review of the various theoretical efforts to study the energy loss of ions in matter is presented. The first part of the paper, mainly of a tutorial character, deals with classical scattering theory and some fundamental concepts useful for further study. In the second part, the main theories for high-energy and low-energy electronic stopping are reviewed and then the difficulties in describing intermediate-energy stopping are discussed. Finally, the various approaches (empirical, semi-empirical, semi-phenomenological and first principles) that have led to satisfactory descriptions of the energy loss for the whole (non-relativistic) energy range are considered.

ISSN:0033-7579    

DOI:10.1080/00337578608207480

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

On the assumption that the lattice location of implanted impurities is determined by the local chemical bond, the impurity sites of various groups of (non-transition) elements of the Periodic Table implanted in pure silicon are discussed in terms of their valency. The theoretical results are in reasonable agreement with available experimental data.

ISSN:0033-7579    

DOI:10.1080/00337578608207481

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The isothermal oscillatory behaviour of radiation damaged crystalline chemical compounds is revealed by both radiochemical and neutron diffraction methods. Low temperature reactor irradiation experiments indicate the major role of the existence of defects in a periodic reaction of re-establishment of the parent lattice affecting both the amplitude and the frequency of the oscillations. Simple chemical compounds like CaF2and NaCl present the same oscillatory characteristics when examined by neutron diffraction as those obtained by radiochemical analysis in complex compounds. Comparison of the oscillations taken in the same compound by both methods reveals the strong connection between a macroscopically detected phenomenon of radiation damaged lattice and a radiochemical evidence of periodic reactions at the tracers' level. The whole phenomenon is speculated as an oscillatory variation of the properties of defects acting as dissipative structures in an open system being far from equilibrium, according to thermodynamics of irreversible processes. A modified Lotka model is being used.

ISSN:0033-7579    

DOI:10.1080/00337578608207482

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Based on the general Gaudsmit-Saunderson-Lewis model for multiple scattering in a semi-infinite medium, an expression accounting for the effects of multiple scattering on the shape of the backscattering energy spectrum has been obtained. This expression is represented by a series of ion angular distribution moments. The limits of the applicability of the small-angle approximation to the description of multiple scattering are defined. It is shown that the sensitivity of the angular distribution moments of multiple scattered ions to the type of ion-atom potential increases with an increase in the moment order. The possibility of investigation of the ion-atom interaction potential experimentally over a wide range of impact parameters by the backscattering method is discussed.

ISSN:0033-7579    

DOI:10.1080/00337578608207483

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Experimental and theoretical results are presented on Tl-ion implantation into hot silicon substrates (⋍1200°C).

ISSN:0033-7579    

DOI:10.1080/00337578608207484

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The spontaneous radiation of electrons and positrons during channeling in crystals with a superlattice was investigated under resonance conditions when the energy difference between two levels characterizing the transverse motion in the averaged potential of the channel is approximately a multiple of 2πhc/l, wherelis the superlattice period along the channel axis. It is shown that there is splitting of the total energy levels of electrons under the influence of a spatially periodic perturbation. This splitting causes the essential change of spectral-angular dependence of the radiation power. The splitting of several Kumakhov radiation bands during electron channeling is predicted. The value of the splitting is estimated. It is shown that there is no splitting in the spectrum of the channeling radiation of positrons.

ISSN:0033-7579    

DOI:10.1080/00337578608207485

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The effect of decreasing the defect generation rate in GaAs samples, which were previously irradiated by supercurrent ion beams under certain conditions, is discussed.

ISSN:0033-7579    

DOI:10.1080/00337578608207486

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A technique which allows the depth distribution of anN-elemental target composition from Rutherford backscattering spectra to be obtained is presented. Using this technique one can calculate the ratio of the atomic concentration of each element to the total atomic concentration at some depth. The depth scale is determined in atoms/cm2. The contributions from all target constituents to the stopping of probe ions are taken into account. The stopping power is given by Bragg's rule. The individual RBS yields fromN-1 constituents are required to apply the technique.

ISSN:0033-7579    

DOI:10.1080/00337578608207487

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A two-dimensional Fokker-Planck equation is solved for the distribution function of channeled electrons for different depths. The influence of type, temperature and orientation of a crystal on the spontaneous radiation of channeling electrons is examined also.

ISSN:0033-7579    

DOI:10.1080/00337578608207488

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The effect of oxygen plasma exposure on the motion of mobile ions in SiO2-Si structures has been investigated. The ion transport was found to be limited by ion traps at the outer surface. A plasma-induced mobilization effect was observed only at 300°C substrate temperature during plasma exposure. At lower temperatures some interrelation of Na and H ions is suggested based on the behaviour of the different charge centres.

ISSN:0033-7579    

DOI:10.1080/00337578608207489

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor