The giant dielectric tunability effect in bulk La2NiMnO6 around room temperature

The effect of applied dc bias electric field on dielectric permittivity in bulk La2NiMnO6 is investigated in this paper. It is found that a small bias field of 40 V/cm can greatly reduce the dielectric permittivity around the room temperature, compared to the much larger electric field that is required for conventional ferroelectric materials. The observed giant dielectric tunability is retained over a broad range of around room temperature and is most likely related to the charge ordering of Ni2+ and Mn4+ ions, further confirming the existence of electronic ferroelectricity in La2NiMnO6.