On the influence of uncertainties in scattering potentials on quantitative analysis using keV ions

Abstract

Experimental spectra from medium energy ion scattering were compared to Monte-Carlo simulations (employing the TRBS code) to obtain information on the scattering potential. The impact of uncertainties in the interatomic potential on quantification of sample properties such as thickness, composition or electronic stopping was investigated for different scattering geometries: backscattering and transmission. For backscattered He ions with tens of keV primary energy the scattering potential was found to overestimate the multiple scattering background in the energy spectra resulting in an uncertainty of < 3 % in quantitative analysis. Light ions transmitted through a sample for equivalent path length in the medium are only affected minorly by changes in the scattering potential. This effect becomes more distinct for heavier primary ions.

Impact of the experimental approach on the observed electronic energy loss for light keV ions in thin self-supporting films

“…Note, that also towards the trailing edge in the backscattering spectrum the simulation slightly overestimates the intensity of the spectrum, which could be missing intensity due to certain trajectories featuring an energy loss lower than average. However, also deficiencies of the scattering potential could in general explain a difference in the plateau height [26], while, the good agreement between simulation and experiment in the multiple scattering background renders this interpretation rather unlikely. To further investigate the high energy component in the spectrum of transmitted particles, different scattering geometries are studied.…”

“…The employed TRBS code (TRIM for backscattering) allows to disentangle electronic and nuclear stopping [25]. The simulations included in this manuscript are performed using the thickness of the sample as well as bulk and surface contaminations as obtained from RBS and ERDA, and the TFM potential, which was found to yield good agreement for the multiple scattering background [26,27]. Convolution of simulated energy spectra by a Gaussian accounts for the finite energy resolution of the primary beam.…”

Electronic excitation of transition metal nitrides by light ions with keV energies

“…A recent study investigates the influence of uncertainties in the scattering potential on the evaluation of electronic energy loss. As a result, the evaluation of the peak width for energies E 0 100 keV may require differences in electronic stopping, necessary to obtain a good fit, up to ∼3% depending on the employed potential, ZBL or Thomas-Fermi-Moliere, and a possible screening correction [55].…”

Определение Потенциала Взаимодействия Ион-Твердое Тело Из Спектров Обратнорассеянных Частиц

“…При моделировании энергетических спектров рассеянных частиц с помощью компьютерных кодов отмечалась необходимость корректировки константы экранирования в потенциале для лучшего согласия с экспериментом [13]. В нашей работе [14] при исследовании эффекта радужного рассеяния атомов на поверхности металлических кристаллов из экспериментальных данных для большого числа систем были получены потенциалы взаимодействия, которые сильно отличаются от потенциалов, используемых для описания рассеяния в газовой фазе.…”