Effect of antiferromagnetic order on the dielectric properties of Bi2Fe4O9

Abstract

We investigated the dielectric and magnetic properties of Bi2Fe4O9 single crystals. The dielectric anomalies observed at the magnetic transition temperature indicate that there is a strong coupling between the magnetic and dielectric properties. The anisotropic magnetic contribution of the dielectric constant is discussed in terms of the spin correlation function, ⟨Si⋅Sj⟩, below the antiferromagnetic transition at 240 K.