Marco Vas: The Lord of the Magnetic Rings

<p dir="ltr">Cu₂OSeO₃ is a unique magnetic material that hosts skyrmions – tiny vortexes of magnetic spins that have potential in future low-energy data-storage. The magnetic behaviour arises from its crystal structure, which leads to special interactions between copper atoms, which allow for the formation of skyrmions. In this study, we modified Cu₂OSeO₃ samples by partially replacing copper atoms with cobalt using solid-state methods. Using neutron powder diffraction, it was confirmed that the dopants were successfully incorporated into the structure, expanding the crystal lattice. Using Small-Angle Neutron Scattering (SANS), it was determined that Co-doping made it easier to form skyrmions by reducing the required magnetic field and extending their stability across a wider temperature range. We also observed a new magnetic phase not previously seen in SANS measurements of polycrystalline samples. This work shows that chemical changes can tune complex magnetic behaviours, offering insight into designing new materials for advanced data-storage applications.</p>