A study of the dechanneling of protons in SiC polytype crystals in the energy range Ep=400-650 keV

In the present work, the energy spectra of protons channeled along the (0 0 0 1) axis of SiC polytype crystals (namely 4H and 6H) in the energy range Ep=400-650 keV, in the backscattering geometry, were taken and analyzed. Computer simulations are in very good agreement with the measured spectra. The accurate reproduction of the experimental channeling spectra in the backscattering geometry is strongly based on the investigation of the correct dechanneling function and α, the ratio of the stopping powers in the aligned and random mode. In the present work, the applicability of a Gompertz type sigmoidal dechanneling function, with two parameters, k and xc, which represent characteristic dechanneling rate and range, respectively, is examined, and the results are compared to the ones obtained in the past, concerning the same polytype structures, based on the assumption that the dechanneling of protons follows an exponential law, for the energy range Ep=1.7-2.4 MeV