MS-1: Recent developments in surface microscopy

Organiser: Dr. Matthew Bergin, University of Newcastle, Australia

About this Mini-Symposia:
Microscopy of surfaces is growing in importance due to surface structure being essential to the development of technologically important materials such as 2D materials. While established techniques such as AFM, TEM and Raman spectroscopy offer valuable insights into 2D materials, use of either an energetic or scanning probe can lead to surface damage or ambiguity around which features truly lie at the surface. In contrast, atom scattering offers a unique approach with exceptional sensitivity to the electron density above the top layer of atoms due to its low-energy (<100meV) nature. The relatively heavy mass of atoms means that the probe matter wave maintains a small wavelength (~0.05nm) at low energy, permitting the study of nanoscale features of a sample surface. Scanning helium microscopy (SHeM) uses a spatially resolved beam of helium atoms to exploit this sensitivity to image surfaces. Recent developments allow new spatially resolved measurement possibilities including mapping local lattice properties across a sample, such as spacing and orientation of an atomic lattice.

This mini-symposium aims to bring together researchers who are interested in developing and applying new and existing techniques for imaging 2D material surfaces. The session will focus on providing important insights into recent work and fostering further discussion on the application of these techniques.

Scientific Topic:
2D materials, atom scattering, scanning helium microscopy, surface microscopy.

Research Scope:
Studies of surface phenomena require tools with exceptional sensitivity to the outermost atomic layer of a material. Such surface phenomena are critical to the understanding of many disciplines, including the growing field of 2D materials. Atomic beams provide a low energy probe that, when collimated, can be used to spatially image a surface with unique sensitivity to the surface structure. Recent work has demonstrated the sensitivity to atomic-scale topography of a gold sample (Nat Commun 14, 904 (2023)) and the ability to harness the matter wave character of the helium beam to measure diffraction patterns from a surface atomic lattice (PRL 131, 236202).

Expected Audience Type:
Surface microscopists, atom scattering community.