Study of complex phase transitions in hexagonal RbCoBr3

Abstract The complex phase transitions involving magnetic and structural ordering in an Ising-like antiferromagnet RbCoBr 3 were studied by some magnetic, calorimetric and dielectric means. In particular, from the transverse magnetic susceptibility measurement, xy -components of Co 2+ pseudo-spin was confirmed to produce a weak moment below T N1 (37.0 K) in the basal c-plane. A probable mechanism to yield the moment was attributed to the Dzyaloshinskii–Moriya interaction between Co 2+ ’s along the c -axis, which is inherent to the lattice distortion brought about by the ferroelectric phase transition of this system.