Structure, dielectric and magnetodielectric properties of Bi_(1-x)Gd_xFeO_3 Ceramics

作     者：李静波 饶光辉 肖荫果 骆军 刘广耀 陈景然 梁敬魁 

作者机构：Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Institut fuer Festkoerperforschung Forschungszentrum Juelich D-52425 Juelich Germany International Centre for Materials Physics Chinese Academy of Sciences 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2010年第19卷第10期

页      面：554-560页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Project supported by the National Basic Research Program of China (Grant No. 2007CB925003) the National Natural Science Foundation of China (Grant No. 50872148) 

主　　题：multiferroic magnetodielectric effect x-ray diffraction Bi1-xGdxFeO3 ceramics 

摘      要：Different magnetodielectric effects were observed in Bi1-xGdxFeOa ceramics depending on gadolinium content. A positive one was observed in the samples with x ≤ 0.10 at 295 K and 16 K, and a negative one in the sample with x = 0.4 at 16 K. Structure analysis by x-ray diffraction （XRD） reveals that the samples crystallize in the R3c structure （ferroelectrics） for x 〈 0.08 and in the Pbnm structure （paraelectrics） for x ≥ 0.3 at room temperature. Temperaturedependent dielectric response and x-ray diffraction confirm the occurrence of a structural transition in the Pbnm phase at low temperature for the samples with x ≤0.4. While the positive magnetodielectric effects can be attributed to a coupling of magnetic and crystallographic structures of the R3c phase, the observed negative magnetodielectric effect in the Pbnm phase can be associated with a low-temperature modification of the Pbnm structure. The observed dualsigned magnetodielectric effects suggest that the Bi1-xGdxFeO3 oxides are a good prototype for understanding the magnetodielectric coupling mechanism in this kind of materials.