| Popis: |
The difficulties of depth profiling in single crystals, using MeV light ion beams, are discussed with particular emphasis on planar channeling effects. Depth profiling of 18 O self-diffused crystals (corundum, Al 2 O 3 ; forsterite, Mg 2 SiO 4 ) via the 18 O(p, α ) 15 N nuclear reaction is used as an illustration. The effects on the alpha spectrum of channeling the proton beam along major axes and planes are described. There is a high probability that planar channeling effects distort the spectra strongly when the proton beam is incident on the crystals off axis but with any azimuthal orientation. A simple routine procedure is presented to minimize such unwanted effects, based on a combined use of nuclear reaction depth profiling and RBS techniques. |
