Dielectric dispersion and charge ordering of LuFe₂O₄

A layer-structure oxide LuFe₂O₄ shows dielectric dispersions in two temperature regions below and above the transition between two- and three-dimensional charge orderings proposed by a diffraction study. The origin of the dispersions are considered to be related with electron hopping between Fe²⁺ and Fe³⁺ ions ordered or disordered on triangular lattices characteristic of this oxide.