[15p-502-1~8] Approaching the Crystal Properties of Metal Oxide

[15p-502-4] Dielectric Properties of Rare-earth Iron Oxides, RFe₂O₄

〇Katsuhisa Tanaka¹, Shinya Konishi¹, Takahisa Arima² (1.Kyoto Univ., 2.Univ. Tokyo)

Keywords:dielectric properties, oxides, magnetic properties

RFe₂O₄ (R=rare-earth, In) has attracted considerable attention since one of the compounds, LuFe₂O₄, was suggested to be ferroelectric in 2005. The ferroelectricity was considered to originate in the polarization formed between two neighboring layers composed of Fe³⁺ and Fe²⁺ ions. Nonetheless, whether the compounds are actually ferromagnetic or not has been a controversial issue, and the microscopic origin for the dielectric properties still remains unclear. Recently, mainly by using piezoresponse force microscopy, we have revealed that some of the compounds of RFe₂O₄ system, i.e., YFe₂O₄, TmFe₂O₄, and LuFe₂O₄ are ferroelectric as well as piezoelectric at room temperature. In the presentation, we discuss about the details of dielectric properties of single-crystalline RFe₂O₄ on the basis of our experimental data.