Ho掺杂BiFeO3陶瓷的制备及介电性能  

PREPARATION AND DIELECTRIC PROPERTIES OF Ho-DOPED BiFeO_3 CERAMICS

作　　者：常方高[1] 胡棚[1] 王丹丹[1] 宋桂林[1] 朱美玲[1] 

机构地区：[1]河南师范大学物理与信息工程学院,河南省光伏材料重点实验室,河南新乡453007

出　　处：《硅酸盐学报》2010年第6期1002-1006,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(60571063);教育部留学回国人员科研启动基金(教外司留[2005]55);河南省教育厅自然科学研究计划(2006700014)资助项目

摘　　要：采用快速液相烧结法制备Ho掺杂BiFeO3系列陶瓷样品Bi1–xHoxFeO3(x=0,0.05,0.1,摩尔分数),X射线衍射物相分析表明:样品均为三方钙钛矿结构,掺杂微量的Ho3+可以有效消除样品中的Bi2Fe4O9杂相,获得单相Bi0.95Ho0.05FeO3。用HP4294A精密阻抗分析仪测量样品介电特性随频率、温度及偏置电压的变化关系,结果表明:Ho掺杂样品的室温相对介电常数(εr)比未掺杂的显著提高,测量频率为40Hz时,Bi0.9Ho0.1FeO3陶瓷样品的εr提高了1个数量级;观测到样品的介电峰,掺杂后介电峰向低温移动且强度显著增加,表明Ho掺杂在降低样品反铁磁Néel温度的同时增强了磁电耦合效应。讨论样品εr随偏置直流电压的变化关系,掺杂后出现明显的介电回滞现象,Ho掺杂可提高样品的剩余极化强度,改善样品的铁电性质。Polycrystalline Bi1–xHoxFeO3 ceramics （x = 0,0.05,0.1,mole fraction） were prepared by the rapid liquid phase sintering method. The X-ray diffraction patterns show that Bi1–xHoxFeO3 ceramics are rhombohedral perovskite structure. Ho substitution eliminates the impurity phase Bi2Fe4O9 and single phase Bi0.95Ho0.05FeO3 ceramic is obtained. The frequency,temperature and bias voltage dependences of dielectric properties of Bi1–xHoxFeO3 samples were measured using a HP4294A precision impedance analyzer. The results show that,the relative dielectric constant （εr） of Bi0.95Ho0.1FeO3 samples increased significantly by doping Ho which is enhanced by an order of magnitude at 40 Hz; in the dielectric constant spectra,the peaks of doped samples shift to the lower tempera-ture and the intensity increased significantly,indicating that Ho doping reduces Néel temperature （θN） while enhancing the magneto-electric effect of samples; the curves of relative dielectric constant vs direct current bias voltage shows a clear dielectric hysteresis in doped samples indicating Ho doping increases the remanent polarization and improves the ferroelectric properties of samples.

关 键 词：铁磁电材料 掺杂 介电特性 偏置电压 

分 类 号：O469[理学—凝聚态物理]