相扩散阻挡法制备铁酸钴/改性钛酸铋钠0-3复合多铁性陶瓷  

Fabrication of the Cobalt Ferrite/Modified Sodium Bismuth Titanate 0-3 Multiferroic Composites via Diffusion-blocking

作　　者：韩权威[1] 李坤[1] 彭松[2] 王雨[3] 陈王丽华[3] 

机构地区：[1]江苏工业学院材料学院,常州213164 [2]南京大学物理系,南京210093 [3]香港理工大学应用物理系及材料研究中心

出　　处：《无机材料学报》2011年第5期486-490,共5页Journal of Inorganic Materials

基　　金：Hong Kong PolyU Project;NSFC/RGC N-PolyU501/08 ME Device

摘　　要：通过溶胶-凝胶工艺在CoFe2O4(简称CFO)粉体表面包覆二氧化锆陶瓷层来阻挡烧结过程中铁磁相与铁电相之间的离子扩散.包覆后的CFO与0.92(Bi0.5Na0.5)TiO3-0.02(Bi0.5K0.5)TO3-0.06BaTiO3(简称BNBT)陶瓷粉体分别按照xCFO/(1-x)BNKLABT(质量分数x=0.05、0.10、0.15、0.20、0.25、0.30)混合均匀,并用聚乙烯醇为粘结剂模压成圆片;再经过1050℃烧结制备了铁磁/铁电0-3型复合材料.XRD分析表明:二氧化锆在高温烧结过程中对离子扩散具有良好的阻挡作用.复合陶瓷的耐击穿电压大于75kV/cm.测量结果表明:复合陶瓷的压电应变常数、机电耦合系数、介电常数和剩余极化随CFO含量的增加而降低;磁电耦合系数、介电损耗随CFO含量的增加而有所增大.φ35mm×1.5mm的复合陶瓷样品(x=0.05)在谐振频率(90kHz)和199kA/m偏置磁场下的磁电系数为1.39V/A.The ZrOz buffer layer was coated on CoFezO4（CFO） powder via a Sol-Gel method. The coated CFO and 0.92（Bi0.sNa0.5）TiO3-0.02（Bi0.sK0.5）TiO3-0.06BaTiO3（BNBT） ceramic powder were mixed according to the chemical formula of xCFO/（1-x） BNBT （weight fraction x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30）. Using polyvinyl alcohol （PVA） as binder, the mixture was pressed into disks. After sintered at 1050~C, the xCFO/（1-x） BNBT 0-3 composite ceramic disks were prepared. The X-ray diffraction results show that the ZrO2 layer can buffer the Fe3＋ and Co2＋ ions diffusing from CFO to BNBT during the sintering process. The break-down voltage of the co-fired composites is measured to be 75kV/cm. It is found that the piezoelectric constant, electromechanical coefficient, remnant polarization and dielectric permittivity decrease as the CFO content increasing. Magnetoelectric coeffi- cient （ME） and dielectric loss increase with the CFO content increasing. For a composite disk with dimension of Ф35mm× 1.5mrn, the ME coefficient at resonance frequency of 90 kHz is 1.39V/A under a DC magnetic bias of 199 kA/m.

关 键 词：磁电效应 0-3复合 铁电 铁磁 

分 类 号：O482[理学—固体物理] TB332[理学—物理]