铁电相BiFeO_3对多铁复合薄膜CoFe_2O_4-BiFeO_3铁磁性能的影响  

Influence of the BiFeO_3 phase on ferromagnet properties of layered multiferroic CoFe_2O_4-BiFeO_3 films

作　　者：刘艳清[1] 吴钰涵[1] 张静[1] 张永军[1] 

机构地区：[1]吉林师范大学功能材料物理与化学教育部重点实验室,四平136000

出　　处：《复合材料学报》2013年第5期132-137,共6页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金项目(61178074);国家自然科学基金青年科学基金项目(10904050);吉林省科技发展计划项目(201115218,201215223);江苏省自然科学基金项目(BK2010348)

摘　　要：为了研究铁电相BiFeO3对复合薄膜磁性能的影响,在LaNiO3(LNO)缓冲层的Si(100)衬底上旋涂制备了含有0、6、9、10层等不同厚度BiFeO3的层状CoFe2O4-BiFeO3(CFO-BFO)多铁复合薄膜。采用XRD、SEM以及TEM对其结构和形貌进行了表征,采用振动样品磁强计测量磁性,研究了不同厚度BFO对复合薄膜磁性的影响。结果表明:CFO和BFO在异质结构薄膜中共存。缓冲层LNO和铁磁相CFO薄膜具有精细微观结构及明显界面。铁电相BFO的厚度对CFO-BFO复合薄膜的磁性能产生了很大影响。在含有不同层数铁电相BFO的复合薄膜中,含有9层BFO复合薄膜的饱和磁化强度最大,达到了230emu·cm-3,相比无铁电相BFO的薄膜,饱和磁化强度提高了18.6%。初步讨论认为:随着铁电相BFO厚度的增加,CFO与BFO之间的应力传导引起了复合薄膜饱和磁化强度的提高。Multiferroic layered films consisting of CoFe2 04 - BiFeO3 （CFO - BFO） with increasing BFO constituent layers thicknesses were prepared on the LaNiO3 （LNO）-buffered Si（100） substrate via a simple spin coating process in order to investigate the thickness effect of ferroelectric BiFeO3 phase on the magnetic properties of the composite films. The structure and morphology were researched by XRD, SEM and TEM. Bisides, the magnetic properties were demonstrated by vibrating sample magnetometer （VSM） and the effect of different thicknesses of BFO layer on the magnetic properties of the composite films was discussed. The results reveal that magnetic CFO and ferroelectric BFO phases coexist in the heterostructured films. The buffered layer LNO and ferromagnetic layer CFO possess clear microstructure and obvious interface between them. The thickness of BiFeO3 phase has a significant influence on the magnetic properties of the CFO - BFO films. Among the multiferroic films containing different BFO layers, the film that consisting of nine BFO constituent layers demonstrates the highest M,value of 230 emu ~ cm- ：3, which improves 18.6% than that of the film without BFO constituent layers. We initially conclude that it is stress that leads to the improvement of M^with increasing the BFO thickness.

关 键 词：层状多铁复合薄膜 旋涂 BFO厚度 磁性 高分辨透射电子像 应力 

分 类 号：TB332[一般工业技术—材料科学与工程]