Electronic charge transfer driven by spin cycloidal structure

The spin cycloidal structure is known as the origin of ferroelectricity in the magnets that are called multiferroics. Although these materials have been studied intensively for some decades, the local ferroelectric mechanism remains elusive. Here, the authors demonstrate that local charge transfer at ligand oxygen sites is driven by the spin cycloidal structure. They achieve this by observing induced spin polarization at oxygen sites with the use of synchrotron x-ray and muon spin rotation techniques. This leads to a better understanding of local electromagnetic coupling in multiferroics.