溶胶-凝胶法制备了Bi1-xBaxFe1-yMnyO3陶瓷样品,研究掺杂对BiFeO3(BFO)的微观结构、磁性及介电性能的影响。XRD表明Bi1-xBaxFe1-yMnyO3为单相菱方钙钛矿结构,BiFeO3的磁滞回线表明其在室温具有反铁磁性(弱铁磁性),Ba和Mn掺杂后使体系由反铁磁性向铁磁性转变。BiFeO3和Bi0.9Ba0.1FeO3介电常数随温度变化曲线在200和230K下均出现转变点,但掺杂Mn时体系转变点消失。当外加磁场时,介电常数的测量表明Ba和Mn掺杂能够增大BFO的磁介电效应。
The Bi1-xBaxFe1-yMnyO3 ceramic samples were prepared by sol-gel process.XRD analysis showed that it was the single-phase rhombohedral perovskite structure.Magnetic hysteresis loops were observed in substituted specimens,and Ba and/or Mn substitution transformed anti-ferromagnetic(weak ferromagnetic) BiFeO3 into ferromagnetic.The dielectric constant measured in BiFeO3 and Bi0.9Ba0.1FeO3 showed two phase transitions below room temperature,which were 200 and 230K.The dielectric constant under the external magnetic field showed that the Ba-Mn codoped BFO sample has greater magneto-dielectric effects.