Mn^(4+)掺杂对BiFeO_3陶瓷微观结构和电学性能的影响研究  

Effect of Mn^(4+) doping on the microstructure and electrical property of BiFeO_3 ceramic

作　　者：张强[1] 朱小红[1] 徐云辉[1] 肖云军[1] 高浩濒[1] 梁大云[1] 朱基亮[1] 朱建国[1] 肖定全[1] 

机构地区：[1]四川大学材料科学与工程学院,成都610064

出　　处：《物理学报》2012年第14期129-135,共7页Acta Physica Sinica

基　　金：教育部新世纪优秀人才支持计划(批准号:NCET-10-0582);教育部博士点新教师基金(批准号:20100181120021);四川省杰出青年学术技术带头人培育计划(批准号:2011JQ0021)资助的课题~~

摘　　要：利用传统的固相反应法制备了BiFe_(1-x)Mn_xO_3(x=0-0.20)陶瓷样品,研究了不同Mn^(4+)掺杂量对BiFeO_3陶瓷密度、物相结构、显微形貌、介电性能和铁电性能的影响.实验结果表明:所制备的BiFe_(1-x)Mn_xO_3陶瓷样品的钙钛矿主相均已形成,具有良好的晶体结构,且在掺杂量x=0.05附近开始出现结构相变.随着Mn^(4+)添加量的增加,体系的相结构有从菱方钙钛矿向斜方转变的趋势,且样品电容率大幅度增大,而介电损耗也略有增加;在测试频率为10~4Hz条件下,BiFe_(0.85)Mn_(0.15)O_3(ε_r=1065)的ε_r是纯BiFeO_3(ε_r=50.6)的22倍;掺杂后样品的铁电极化性能均有不同程度的提高,可能是由于Mn^(4+)稳定性优于Fe^(3+),高价位Mn^(4+)进行B位替代改性BiFeO_3陶瓷,能减少Bia+挥发,抑制Fe^(3+)价态波动,从而降低氧空位浓度,减小样品的电导和漏电流.Multiferroic BiFe_（1-x）Mn_xO_3（x = 0,0.05,0.10,0.15,0.20）（represented as BF_（1-x）M_xO） ceramics are prepared by the conventional solid state reaction technique.The effects of Mn^（4＋） doping on density,phase structure,morphology,dielectric and ferroelectric properties are investigated.The X-ray diffraction patterns of the samples indicate that the typical perovskite phase structure of BiFeO_3 is formed,and a phase transition starts near x=0.05,i.e.,the phase structure is distorted from rhombohedral to orthorhombic by Mn^（4＋） doping.The dielectric susceptibility of the sample is significantly increased and the dielectric loss is slightly increased with the increase of Mn^（4＋） content.The dielectric constantε_r of the BiFe_（0.15）Mn_（0.15）O_3 ceramic at 10 kHz is as high as 1065,22 times larger than that for pure BiFeO_3 It is suggested by hysteresis loop measurements that the ferroelectric property of the BF_（1-x）M_xO ceramics is improved and the remanent polarization is increased by Mn^（4＋） doping.This is probably because Mn^（4＋） is more stable than Fe^（3＋）, and the B-site doping with higher valent Mn^（4＋） could reduce the volatilization of Bi^（3＋） and suppress the valence fluctuation of Fe^（3＋）, thereby reducing the concentration of oxygen vacancies and the leakage current in the ceramic.

关 键 词：Mn^(4+)掺杂 BiFe_1-xMnxO3陶瓷 微观结构 电学性能 

分 类 号：TQ174.1[化学工程—陶瓷工业]