Magnetic dipolar correlations in sillenite-structure bismuth ferrite: magnetic and Mössbauer effect studies

Abstract

Results of the magnetic and Mössbauer effect studies of the polycrystalline Bi25FeO39 sillenite-structure bismuth ferrite are reported. A deviation of the magnetic susceptibility temperature dependence below 50 K from the Curie law is found that we relate to an onset of antiferromagnetic correlations due to the magnetic dipole-dipole interaction. The value of the Néel temperature less than 0.5 K is estimated. Mössbauer spectrum is represented by a single Lorentz-shape line down to 5 K that experiences significant broadening on cooling. Possible mechanisms of this broadening are discussed.