Investigation of the high temperature phase transitions in BaFe2O4

γ-BaFe2O4 shows antiferromagnetism and an improper ferroelectricity at room temperature. The latter is caused by the simultaneous presence of two non-polar distortion modes of the FeO4 units, namely the in-plane rotation of such units and the up-up-up-up-up-down ordering of the apical oxygens around the hexagonal cavities. In the proposed experiment we would like to explore the two phase transitions observed at high temperatures (above 1038 K) and characterize the ferroelectric to paraelectric phase transition.

γ-钡铁氧体（γ-BaFe₂O₄）在室温下表现出反铁磁性与非本征铁电性。后者源于FeO₄单元两种非极性畸变模式的同时存在，即该单元的面内旋转，以及六边形空腔周围顶端氧原子的“上-上-上-上-上-下”有序排列。在拟开展的实验中，我们旨在探究高温（1038 K以上）下观测到的两种相变，并表征铁电相向顺电相的转变过程。