Preparation and structural characterisation of pure and Te-doped Cu₂OSeO₃

Full text: Cu₂OSeO₃ is a multiferroic materials that shows the formation of skyrmions at low temperatures. A skyrmion is a topologically protected particle-like magnetic spin structures on the order of 10-100 nm. Recent studies have also shown that the skyrmions can be manipulated through applications such as an external electric fields and heat. This offers the potential for development for a much more stable, energy efficient and faster storage in memory devices. The magnetic skyrmions pack into a hexagonal lattice with the skyrmion lattice only stable in a narrow magnetic field-temperature range [1,2]. Here we present the preparation of pure and Te-doped Cu₂OSeO₃ single crystals with chemical vapour transport, the structural characterisation with X-ray and neutron single crystal diffraction, small angle neutron scattering and magnetisation measurements. Mapping of the magnetic field-temperature phase diagram showed that tellurium doping resulted in an enlarged stability range for the skyrmion phase had been achieved [3]. (author)