Growth and helicity of non-centrosymmetric Cu$_2$OSeO$_3$ crystals

TL;DR

This paper presents an optimized chemical vapor transport method using SeCl4 to grow large, high-quality Cu2OSeO3 crystals, enabling better control of crystal size, quality, and chirality, with confirmed magnetic properties.

Contribution

The authors developed a more efficient and simpler growth technique for Cu2OSeO3 crystals using SeCl4, achieving larger sizes and high quality compared to traditional methods.

Findings

Successfully grew large Cu2OSeO3 crystals with high quality

Confirmed crystal structure and chirality using X-ray diffraction

Magnetic properties consistent with previous reports

Abstract

We have grown Cu$_2$OSeO$_3$ single crystals with an optimized chemical vapor transport technique by using SeCl$_4$ as a transport agent. Our optimized growth method allows to selectively produce large high quality single crystals. The method is shown to consistently produce Cu$_2$OSeO$_3$ crystals of maximum size 8 mm x 7 mm x 4 mm with a transport duration of around three weeks. We found this method, with SeCl$_4$ as transport agent, more efficient and simple compared to the commonly used growth techniques reported in literature with HCl gas as transport agent. The Cu$_2$OSeO$_3$ crystals have very high quality and the absolute structure are fully determined by simple single crystal x-ray diffraction. We observed both type of crystals with left- and right-handed chiralities. Our magnetization and ferromagnetic resonance data show the same magnetic phase diagram as reported earlier.