摘要
利用脉冲激光沉积法,在3种不同取向的NSTO基片上,生长得到3种不同取向的Fe3O4外延薄膜。制备了Fe3O4(100)/NSTO(100)、Fe3O4(110)/NSTO(110)、Fe3O4(111)/NSTO(111)3种不同异质结。3种异质结的I-V曲线都具有很好的整流特性。利用肖特基结(Schottky junction)二极管I-V关系的热激活模型对实验数据进行处理,得到了这3种异质结的势垒高度ΦB随温度的变化关系。对这3种Fe3O4/NSTO异质结的磁阻进行了测量,分析指出Fe3O4的磁各向异性和不同取向异质结的势垒高度差,是造成3种异质结磁阻差异的主要原因。发现3种异质结的磁阻都与Fe3O4的Verwey转变温度(Tv)相关,在120 K处负磁阻最大。
Fe3O4 epitaxial thin films with three different orientations were grown on three different orientated NSTO substrates. Three different heterojunctions Fe3O4 （100）/NSTO （100）, Fe3O4 （110）/NSTO （110）, Fe3O4 （111）/NSTO （111） were fabricated. The I-V curves of these junctions show rectifying behavior. The temperature dependence of the barrier heightΦB is determined by fitting the I-V curves by using thermoactivation model of schottky junction diode. The magnetoresistance of these Fe3O4/NSTO junctions were investigated. Analysis pointed out that the magnetic anisotropy of Fe3O4 and different orientation of the heterojunction barrier height difference, is caused by three main reasons for heterojunction magnetoresistance of different. The result shows a maximum of magnetoresistance at 120 K indicating that the magnetoresistance is related to the Verwey transition.
出处
《三明学院学报》
2014年第6期56-61,共6页
Journal of Sanming University
基金
国家重点基础研究发展计划(973)项目(2012CB927402)
福建省省属高校科研专项基金项目(JK2010060)
关键词
Fe3O4薄膜
异质结
Ⅰ-Ⅴ曲线
势垒
磁阻
Fe3O4 thin films
heterojunction
I-V curve
barrier
magnetoresistance
