物理学报2012，Vol.61Issue(17)：494-501,8.
Gd，Co共掺杂对BiFeO3陶瓷电输运和铁磁特性的影响
Effects of Gd and Co doping on the electrical and ferromagnetism properties of BiFeO3 ceramics
摘要
Abstract
Multiferroic Bi0.95Gd0.05Fe1-xCoxO3 （x= 0, 0.05, 0.1, 0.15, 0.2） ceramics were prepared by rapid liquid phase sintering method. We studied effect of Gd and Co doping on the structure, electrical and ferromagnetism properties of BiFeO3 ceramics. The structure and morphology of BiFeO3 ceramics are characterized by X-ray diffraction （XRD）. The results show that all the peaks for Bi0.95Gd0.05Fe1-xCoxO3 （x= 0, 0.05, 0.1, 0.15, 0.2） samples can be indexed according to the crystal structure of pure BiFeO3. And X-ray diffraction analysis reveals a phase transition in Gd-Co codoped BiFeO3 ceramics when x is larger than 0.1. The current densities of all samples measured at room temperature are approximately three orders of magnitude lower than that of BFO ceramic, and the leakage current of the ceramics at room temperature exhibits two distinctive conduction behaviors： Ohmic conduction and space charge limited （SCL） conduction mechanism. For all the samples studied here, the dielectric constant and dielectric loss decrease with the increase of frequency in a range from 1 kHz to 1 MHz. The dielectric constants of Bi0.95Gd0.05Fe1-xCoxO3 （x= 0, 0.05, 0.1, 0.15,0.2） samples are nearly 1.9, 2.68, 3.85, 5.3, and 6 times larger than that of pure BiFeO3 （εr= 61.2） ceramic at 1 kHz, respectively. And the dielectric losses of Bi0.95Gd0.05Fe1-xCoxO3 samples become smaller than that of BFO ceramic. The magnetic measurements show that all the samples possess strong ferromagnetism at room temperature expect BiFeO3 and Bi0.95Gd0.05FeO3 which are weakly ferromagnetic. Under an external magnetic field of 30 kOe, the values of Mr of Bi0.95Gd0.05Fe1-xCoxO3 are 34, 60, 105, 103 and 180 times that of BiFeO3, respectively.关键词
铁磁电材料/磁滞回线/漏导电流Key words
multiferroic/magnetic hysteresis loops/leakage current分类
化学化工引用本文复制引用
宋桂林,周晓辉,苏健,杨海刚,王天兴,常方高..Gd，Co共掺杂对BiFeO3陶瓷电输运和铁磁特性的影响[J].物理学报,2012,61(17):494-501,8.基金项目
国家自然科学基金（批准号：60571063）,河南省重点科技攻关项目（批准号：122102210191）,河南省教育厅自然科学研究计划（批准号：2011A140014）和河南师范大学青年基金（批准号：2010qk02）资助的课题 （）
