1 Multiferroic Hysteresis Loop 2

Multiferroics, showing both ferroelectric and magnetic order, are promising candidates 8 for future electronic devices. Especially, the fundamental understanding of ferroelectric switching 9 is of key relevance for further improvements, which however is rarely reported in literature. On a 10 prime example for a spin-driven multiferroic, LiCuVO4, we present an extensive study of the 11 ferroelectric order and the switching behavior as function of external electric and magnetic fields. 12 From frequency-dependent polarization switching and using the Ishibashi-Orihara theory, we 13 deduce the existence of ferroelectric domains and domain-walls. These have to be related to 14 counterclockwise and clockwise spin-spirals leading to the formation of multiferroic domains. A 15 novel measurement – multiferroic hysteresis loop – is established to analyze the electrical 16 polarization simultaneously as a function of electrical and magnetic fields. This technique allows 17 characterizing the complex coupling between ferroelectric and magnetic order in multiferroic 18 LiCuVO4. 19