Magnetoelectric coupling effect in a new multiferroic RbFe(SO4)2

In the past decade, intense efforts have been directed at the discovery of new multiferroic materials. To search new multiferroic materials, a lot of researches have been focusing on frustrated magnets which usually have complicated magnetic structure. For example, multiferroicity has been discovered in a triangular lattice antiferromagnet RbFe(MoO4)2. Recently we successfully grew high quality single crystals of RbFe(SO4)2 which is isostructural to the multiferroic RbFe(MoO4)2. In this work, we will discuss the ferroelectric polarization, dielectric constant and strong magnetoelectric coupling effect in RbFe(SO4)2 single crystals.