The motion of energetic charged particles inside a monocrystalline solid can be strongly influenced by channeling and blocking effects. The present article reviews the theory, the experimental studies, and some of the applications of these effects. The coverage of the published literature extends through June 1973.

Channeling and related effects in the motion of charged particles through crystals

Collisions of atoms and ions with surfaces under grazing incidence

The processes involved when ions bombard surfaces are divided into two categories: those due to elastic collisions, i.e., sputtering and ion scattering; and those due to inelastic collisions, leading to excitation and ionization, resulting in the emission of X-rays, optical photons and electrons. The mechanisms involved in ion scattering and sputtering are reviewed in detail. The experimental energy and angular distributions of the secondary particles are considered and compared with current theories. The effect of sputtering on the erosion of surfaces and the effects of radiation blistering and radiation damage on surface topography are discussed. Considering inelastic effects due to incident ions, results for total yields, statistics of secondary electron emission, and their energy distribution are outlined. X-ray emission, including molecular X-rays and other solid state effects, are discussed. Finally optical photon emission due to de-excitation of excited atoms is treated.

https://iopscience.iop.org/article/10.1088/0034-4885/38/2/002/pdf

The behaviour of surfaces under ion bombardment

The ferromagnetic order is modified near the surface of a magnetic crystal. This modification is studied most clearly in magnetic thin films consisting of only a few atomic layers. Some essential features of the theoretical description are reported as a basis for the discussion of experiments. The main experimental problem is the preparation of flat single crystal films; the real structure of the best available films is discussed. Their magnetic properties are compared with theoretical predictions. Furthermore, methods and results are reported for probing the magnetic properties of surfaces, by their interaction with low energy electrons.

Ferromagnetism near surfaces and in thin films

We investigate the electrical injection of spin-polarized electrons into a semiconductor [Al(GaAs)] heterostructure from ferromagnetic FeCo metal through an ${\mathrm{AlO}}_{x}$ tunnel barrier. We have developed the optical oblique Hanle effect approach for the quantitative analysis of electrical spin injection into semiconductors. This technique is based on the manipulation of the electron spins within a semiconductor when spin polarized electrons have been injected. This allows us to clearly separate the effects caused by spin injection from others, that are magneto-optical, Zeeman, etc. Simultaneously, the oblique Hanle effect approach provides additional information on the spin dynamics in the semiconductor. In the ${\mathrm{F}\mathrm{e}\mathrm{C}\mathrm{o}/\mathrm{A}\mathrm{l}\mathrm{O}}_{x}/\mathrm{Al}(\mathrm{GaAs})$ heterostructures we observe spin injection of 21% and 16% at 80 and 300 K, respectively. The importance of electron thermalization effects and the impact of the doping level of the semiconductor for practical investigation of spin injection by optical means are demonstrated.

Optical investigation of electrical spin injection into semiconductors

http://www.ruf.rice.edu/~rau/papers/p317.pdf

R. Sizmann

Papers

Measurement of predominant electron spin orientation at single crystal surfaces of ferromagnetic nickel

Capture of polarized electrons by deuterons emerging from a magnetized nickel foil

Bound states of swift negative particles in crystals

Location of adsorbed atoms by surface channeling