Observation of diffuse scattering in scanning helium microscopy.

Autor: Lambrick SM; Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. sml59@cam.ac.uk., Bergin M; Centre for Organic Electronics, University of Newcastle, Physics Building, Callaghan, NSW 2308, Australia., Ward DJ; Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. sml59@cam.ac.uk., Barr M; Centre for Organic Electronics, University of Newcastle, Physics Building, Callaghan, NSW 2308, Australia., Fahy A; Centre for Organic Electronics, University of Newcastle, Physics Building, Callaghan, NSW 2308, Australia., Myles T; Centre for Organic Electronics, University of Newcastle, Physics Building, Callaghan, NSW 2308, Australia., Radić A; Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. sml59@cam.ac.uk., Dastoor PC; Centre for Organic Electronics, University of Newcastle, Physics Building, Callaghan, NSW 2308, Australia., Ellis J; Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. sml59@cam.ac.uk., Jardine AP; Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. sml59@cam.ac.uk.
Jazyk: angličtina
Zdroj: Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2022 Nov 09; Vol. 24 (43), pp. 26539-26546. Date of Electronic Publication: 2022 Nov 09.
DOI: 10.1039/d2cp01951e
Abstrakt: In understanding the nature of contrast in the emerging field of neutral helium microscopy, it is important to identify if there is an atom-surface scattering distribution that can be expected to apply broadly across a range of sample surfaces. Here we present results acquired in a scanning helium microscope (SHeM) under typical operating conditions, from a range of surfaces in their native state, i.e. without any specialist sample preparation. We observe diffuse scattering, with an approximately cosine distribution centred about the surface normal. The 'cosine-like' distribution is markedly different from those distributions observed from the well-prepared, atomically pristine, surfaces typically studied in helium atom scattering experiments. Knowledge of the typical scattering distribution in SHeM experiments provides a starting basis for interpretation of topographic contrast in images, as well as a reference against which more exotic contrast mechanisms can be compared.
Databáze: MEDLINE