<strong>Study of the Properties of Co-Substituted Ba₂Mg₂Fe₁₂O₂₂ Hexaferrites</strong>

Abstract

We present results from a study on the influence of the substitution of Mg 2+ cations in the Y-type Ba2Mg2Fe12O22 hexaferrite with magnetic cations, such as Co 2+ , on its structural and magnetic properties. The Ba2Mg0.4Co1.6Fe12O22 powder was synthesized by sonochemical co-precipitation method. The XRD pattern of the powders showed the characteristic peaks corresponding to the Ytype hexaferrite structure as a main phase and some CoFe2O4 impurity (< 2%) as a second phase. This result was also confirmed by Mössbauer spectroscopy measurements. The magnetization values at 50 kOe were 30 emu/g at 4.2 K and 26.6 emu/g at 300 K, respectively. The ZFC and FC magnetization curves were measured at magnetic fields of 50 Oe, 100 Oe and 500 Oe, which revealed a magnetic phase transition around 200 K from ferrimagnetic-to-helical spin order. This is considered as a precondition for the material to exhibit multiferroic properties.