Publication detail

Calcium and fluorine signals in HS-LEIS for CaF2(111) and powder-Quantification of atomic surface concentrations using LiF(001), Ca, and Cu references

PRŮŠA, S. BÁBÍK, P. MACH, J. STRAPKO, T. ŠIKOLA, T. BRONGERSMA, H.

English title

Calcium and fluorine signals in HS-LEIS for CaF2(111) and powder-Quantification of atomic surface concentrations using LiF(001), Ca, and Cu references

Type

journal article in Web of Science

Language

en

Original abstract

The powder of CaF2 has been proposed as a practical reference for the quantitation of Ca and F in low energy ion scattering (LEIS) analysis. It is chemically inert, easy to clean, and inexpensive. LEIS is extremely surface sensitive. Thus, in contrast to surface analytic techniques such as x-ray photoelectron spectroscopy and secondary ion mass spectroscopy, the surface termination of a sample is clearly reflected in the LEIS results. It is, thus, unlikely that in LEIS, the F/Ca ratio for CaF2 is 2.0. This paper supports the reliability of the CaF2 powder reference by evaluating the calcium and fluorine atomic surface concentrations, roughness factor and shows that the surface termination of the powder is the same as that of CaF2(111). The CaF2 samples are treated by annealing at 725 K and measured at 625 K. The presented spectra are practically free of contamination. Ion scattering by LiF (001), an evaporated Ca layer, and a Cu foil are used as basic references for Ca and F. The atomic sensitivity factors and the relative sensitivity factors have been determined for F, Ca, and Cu (3 keV He+, 145 degrees). The F/Ca atomic ratio is found to be the same (2.3 +/- 0.1) for CaF2(111) and its powder. For the powder, the Ca and F signals are reduced by a factor of 0.77 +/- 0.03 in comparison with those for the single crystal.

English abstract

The powder of CaF2 has been proposed as a practical reference for the quantitation of Ca and F in low energy ion scattering (LEIS) analysis. It is chemically inert, easy to clean, and inexpensive. LEIS is extremely surface sensitive. Thus, in contrast to surface analytic techniques such as x-ray photoelectron spectroscopy and secondary ion mass spectroscopy, the surface termination of a sample is clearly reflected in the LEIS results. It is, thus, unlikely that in LEIS, the F/Ca ratio for CaF2 is 2.0. This paper supports the reliability of the CaF2 powder reference by evaluating the calcium and fluorine atomic surface concentrations, roughness factor and shows that the surface termination of the powder is the same as that of CaF2(111). The CaF2 samples are treated by annealing at 725 K and measured at 625 K. The presented spectra are practically free of contamination. Ion scattering by LiF (001), an evaporated Ca layer, and a Cu foil are used as basic references for Ca and F. The atomic sensitivity factors and the relative sensitivity factors have been determined for F, Ca, and Cu (3 keV He+, 145 degrees). The F/Ca atomic ratio is found to be the same (2.3 +/- 0.1) for CaF2(111) and its powder. For the powder, the Ca and F signals are reduced by a factor of 0.77 +/- 0.03 in comparison with those for the single crystal.

Keywords in English

high-sensitivity low energy ion scattering; HS-LEIS; ISS; calcium fluoride; CaF2; lithium fluoride; LiF(001); calcium; Ca; copper; Cu

Released

01.12.2020

Publisher

AIP Publishing

Location

MELVILLE

ISSN

1055-5269

Volume

27

Number

2

Pages from–to

1–13

Pages count

13

BIBTEX


@article{BUT166071,
  author="Stanislav {Průša} and Pavel {Bábík} and Jindřich {Mach} and Tomáš {Strapko} and Tomáš {Šikola} and Hidde H. {Brongersma},
  title="Calcium and fluorine signals in HS-LEIS for CaF2(111) and powder-Quantification of atomic surface concentrations using LiF(001), Ca, and Cu references",
  year="2020",
  volume="27",
  number="2",
  month="December",
  pages="1--13",
  publisher="AIP Publishing",
  address="MELVILLE",
  issn="1055-5269"
}