Dr Samuel Seddon has recently published his paper in Physical Review B titled 'Ferroelastic control of magnetic domain structure: Direct imaging by magnetic force microscopy.'Link opens in a new window

The research was undertaken whilst Sam was studying his PhD at the University of Warwick, under the supervision of Professor Marin Alexe. The project was in collaboration with Sebastian Haines and Michael Carpenter at the University of Cambridge, who had previously identified the material’s strong magneto-elastic coupling – which is to say that the samples magnetic structure is strongly linked to its crystal structure, that forms structural domains. Here, the aim was to spatially resolve the magnetic domains present on the samples surface, and see how they behave under applied magnetic field.

Results show that depending on which structural (ferroelastic) region was present on the samples surface, strongly dictated the local magnetic switching in applied magnetic field. By identifying three different behaviours, it was possible to quantify each set of images and then numerically combine the three behaviours and directly compare them to bulk magnetometry data.

Sam says “this is a really nice example of combining magnetic force microscopy, a local magnetic imaging technique, with bulk magnetometry, a technique that measures an entire sample at once. Imaging an entire sample is impossible, however the quantification of magnetic force microscopy images, which display different local behaviours, allow for a direct fitting of the magnetometry data and allow us to identify the respective proportions of ferroelastic domains present in the entire sample.”

Sam graduated from Warwick in 2022, and is now undertaking a post-doctoral position at Dresden University of Technology, Germany, working on the behaviour of complex crystal asymmetries under applied mechanical strain.