Understanding the origin of magnetoelectric coupling in G-type antiferromagnetic Fe₂TeO₆ through neutron diffraction

Fe₂TeO₆ (FTO) is a magnetoelectric (ME) G-type antiferromagnet with tetragonal trirutile structure (P2/mnm). The magnetic susceptibility and the specific heat of FTO show broad anomaly around 233K before the sharp fall at TN ~ 210K. We observed nonlinear ME behavior above and below TN. This nonlinear behavior signifies the presence of magnetostriction and/or magnetoelasticity in FTO. The analysis of temperature dependent Neutron diffraction (ND) data reveals the local noncentrosymmetry at the Fe site due to d⁵ off-centering of Fe³⁺ with asymmetric p-d hybridization in different Fe-O bonds causing ME coupling in FTO. Crystal and magnetic structure of FTO reveal the possibility of multiple competitive exchange interactions (Fe³⁺-O-Fe³⁺) (author)