| 초록 |
Among several different types of magnetoelectric multiferroic, magnetically induced ferroelectrics in which ferroelectricity is induced by complex magnetic orders, such as spiral orders, have been found in the past several years. Based on the so-called spin-current and the inverse Dzyaloshinskii–Moriya models, hexaferrites have been recently predicted to have a spontaneous electric polarization in a sprial spin ordered state up to room temperature. PbFe12-xGaxO19 is M-type hexaferrite and reported that for x＞3 the spin arrangement becomes non-collinear. Considering the above described backgrounds it is expected that the spontaneous electric polarization can be induced in PbFe12-xGaxO19. We have prepared PbFe12-xGaxO 19 (with x=6) single crystals by the PbO flux up to several millimeters and have measured magnetic, electric and magnetoelectric properties. By measuring temperature and field dependency of magnetization , dielectric constant and electric current, we have found ferrimagnetic transition (at Tc~350K) and phase transition temperature below magnetic transition temperature and the magnetodielectric responses have been investigated. |
