ISSN:0033-7579    

DOI:10.1080/00337577208231133

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The qualitative features of the angular distribution of particles emergent from thin ∼ 1μ, uniform single crystals of silicon and germanium for incidence at small angles to axial directions are discussed in terms of the continuum picture of particle channeling. Blocking of axially channeled particles in the transverse plane is demonstrated. Implications and possibilities arising from observation of non-equilibrium of the transverse momentum vector are discussed. The use of the radial spreading of the angular distribution to investigate the average inter-atomic potential distribution in the plane transverse to the axial direction is explored and perturbations due to multiple scattering in surface films or inside the crystal and to beam divergence are qualitatively considered.

ISSN:0033-7579    

DOI:10.1080/00337577208231134

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Systematic measurements of angular yields have been performed by backscattering of H+and D+impinging along different axes of silicon.

ISSN:0033-7579    

DOI:10.1080/00337577208231135

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The reciprocity in electron diffraction is demonstrated in thin and thick crystals by using an electron microscope with scanning system. It is concluded that the experiment of electron channeling is identical with that of Kikuchi patterns. The diffraction patterns from thin and thick films of silicon, copper and gold are observed with a 1 MV electron microscope and the relations between the channeling and diffraction are studied along various crystal axes. The diffraction can be classified into flower and geometrical patterns. The former is observed for gold and for the <110> axes in silicon and copper. In this case, the classical theory may be applicable, and the ratios between Lindhard's critical angle and the observed one are about 0.65. The relation between channeling and various well known phenomena in electron diffraction is discussed.

ISSN:0033-7579    

DOI:10.1080/00337577208231136

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Oxygen ions (4–40MeV) with various charge states have been used to study the effects of channeling upon emerging charge-state distributions and to determine the effect of channeling upon the charge-changing cross sections involved. At energies above 20 MeV, no true equilibrium is observed even for pathlength of 0.6 μm in Au channels. Instead we find quasi-equilibrium for charge states up to 6 + and strongly pathlength-dependent charge functions for 7 + and 8 + injection. The data are interpreted in terms of interaction with loosely bound outer electrons in Au.

ISSN:0033-7579    

DOI:10.1080/00337577208231137

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A small vacuum pinhole-camera incorporating a diffuse radioactive source and a track-registering film has been used to observe channelling phenomena in thin single crystals. This simple technique provides a striking demonstration of axial and planar channelling without the need for a well-collimated beam of charged particles in high vacuum. The resulting pinhole-channelling pattern is analogous to a blocking pattern in so far as it is a projection of the crystal geometry in real space. As an example a pattern obtained with a (111)-oriented silicon crystal is shown.

ISSN:0033-7579    

DOI:10.1080/00337577208231138

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The spatial distribution of reflected particles was experimentally studied in the case of oblique incidence of 4.5 keV Ar ions on a (001) Cu face along the (110) and (100) planes. The distribution in ejection angles of the reflected particles was found to have several peaks and minima. To explain the results of these reflection experiments a computer study was performed. The shape of the calculated spatial distribution curves appears to be very sensitive to variations of the constants in the interaction potentials. Some features of the spatial distribution of the reflected ions have been shown to be connected to the motion of ions in surface semichannels. The spatial distribution of the neutral component of scattered and sputtered particles was also studied in the experiments. A predominant yield of the sputtered particles was observed not only in the low-index but also in high-index directions.

ISSN:0033-7579    

DOI:10.1080/00337577208231139

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

It has been shown previously that the series of maxima and minima observed in the angular distribution of ions scattered by single crystals or passed through thin films at high ion energies are explained by the channeling effect. This paper studies the channeling effect of alkali ions in W, Mo and KCI single crystals under high vacuum (5. 10−8torr) within the pre-threshold energy range (50–400 eV) where channeling can still be traced.

ISSN:0033-7579    

DOI:10.1080/00337577208231140

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Despite early predictions, channeling effect measurements have not yet been applied to a broad range of problems in semiconductor physics. The sensitivity of the present techniques to dopant atoms and lattice disorder is not high enough to be of general interest and the interpretation of experimental data is often uncertain. One clear area of application is in the field of heavily doped or highly disordered semiconductors; ion implantation is the classic example in this category. Other examples include diffusion, alloying, epitaxial layers, heterojunctions, and compensation effects.

ISSN:0033-7579    

DOI:10.1080/00337577208231141

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Recent progress in the field of hyperfine interactions is surveyed. The perturbed angular correlation technique is described and various applications are discussed. Atom location measurements by hyperfine interactions are compared to similar channeling measurements.

ISSN:0033-7579    

DOI:10.1080/00337577208231142

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor