Polycrystalline Lufe < Sub > 2 < / Sub > O < Sub > 4 < / Sub > Preparation And Dielectric Properties Of Research

Mutiferroic materials have rich physical properties and have great potentiality in modern electronic devices due to its remarkable properties.The electronic ferroelectrics is different from traditional ferroelectrics, for the ferroelectric polarization origin from charge ordering. Recently researches have more focuse on the remarkable properties of this new kind of materials. LuFe2O4belong to the electronic ferroelectrics. Polycrystalline LuFe2O4ceramics was synthesized by solid state reactions at1200℃with a mixed gas flow of CO2and H2. The temperature dependence of zero-field cooled and field-cooled magnetization measurements indicates a clear paramagnetic to ferromagnetic transition in our LuFe2O4samples. The temperature relaxation behavior of LuFe2O4ceramics was investigated by an impendence analyzer in the frequency range from20Hz to1MHz. The contributions of grain boundaries, bulks, and electrodes to the ac conductivity and relaxation processes were identified by fitting the impendence data with an equivalent circuit model. When the temperature is lower than around220K, the bulk effect dominates over the contributions of grain boundaries and electrodes on the dielectric relaxation process. However, with temperature increasing, the electrode effect becomes dominant. The polycrystalline LuFe2O4also show a temperature dependent activation energies for ac conductivities which may relate to non-stoichiometric oxygen deficiency in our samples. In addition, the polymer-assisted deposition method has great advantages to control the valence and the the proportion of different elements, so in this paper we also try to prepare LuFe2O4film by polymer assisted depositon method.