2D Helium Atom Diffraction from a Microscopic Spot

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• Nick von Jeinsen, Surface and 2D Nanoscience, Cavendish Laboratory
• Thursday 01 February 2024, 15:00-16:00
• Mott Seminar Room, Cavendish Laboratory.

If you have a question about this talk, please contact Stephen Walley.

A method for measuring helium atom diffraction with micron-scale spatial resolution is demonstrated in a scanning helium microscope (SHeM) and applied to study a micron-scale spot on the (100) plane of a lithium fluoride (LiF) crystal. The positions of the observed diffraction peaks provide an accurate measurement of the local lattice spacing, while a combination of close-coupled scattering calculations and Monte Carlo ray-tracing simulations reproduce the main variations in diffracted intensity. Subsequently, the diffraction results are used to enhance image contrast by measuring at different points in reciprocal space. The results open up the possibility for using helium microdiffraction to characterize the morphology of delicate or electron-sensitive materials on small scales. These include many fundamentally and technologically important samples which cannot be studied in conventional atom scattering instruments, such as small grain size exfoliated 2D materials, polycrystalline samples, and other surfaces that do not exhibit long-range order.

This talk is part of the Physics and Chemistry of Solids Group series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Centre for Health Leadership and Enterprise
• Featured lists
• ME Seminar
• Mott Seminar Room, Cavendish Laboratory
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• Physics and Chemistry of Solids Group
• School of Physical Sciences
• Thin Film Magnetic Talks

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