Co含量对Co-C纳米复合薄膜磁性能和磁电阻的影响  

Co Content Effect on Magnetic Properties and Magnetoresistance of Co-C Nanocomposite Thin Films

作　　者：唐瑞鹤[1] 吴章奔[1] 姜鹤[1] 杨志刚[1] 张弛[1] 水口将辉[2] 梨弘毅 杨白[3] 于荣海[3] 

机构地区：[1]清华大学,北京100084 [2]日本东北大学金属材料研究所 [3]北京航空航天大学,北京100191

出　　处：《稀有金属材料与工程》2011年第S1期89-92,共4页Rare Metal Materials and Engineering

基　　金：国家重大基础研究(2010CB934602);国家自然科学基金(50729101;50771058);博士点基金(20090002110007)项目

摘　　要：采用磁控共溅射法制备了Co含量介于6.4at%~16.4at%的Co-C纳米复合薄膜。形貌观察表明,Co纳米颗粒均匀分散在C基体中,相邻Co颗粒被C基体较好地分离,样品呈现典型的颗粒薄膜结构。Co颗粒平均尺寸随Co含量增加而增大。薄膜在低温下磁性较强,在室温下磁性较弱;磁化强度随Co含量增加显著提高。当温度为4.2K、磁场为90×79.6kA·m-1时,在Co含量为6.4at%、8.3at%和9.6at%的Co-C薄膜中分别观察到9.1%、4.3%和1.9%的负磁电阻,为碳基磁性颗粒薄膜获得优异磁输运性能提供可能。受微结构变化影响,样品磁电阻值随Co含量的增加而下降。Co-C nanocomposite thin films with Co content of 6.4 at%-16.4 at% were fabricated by magneton co-sputtering. TEM images show that the Co nanoparticles are dispersed uniformly in a carbon matrix, indicating typical granular characteristics. The average Co particle size is enlarged by increasing the Co content. Magnetic hysteresis loops reveal that, as Co content increases, magnetization of Co-C thin films is enhanced distinctly. The samples show high magnetization at low temperature and low magnetization at room temperature. Negative MR of 9.1%, 4.3% and 1.9% were observed for Co-C nanocomposite thin films with Co contents of 6.4 at%, 8.3 at% and 9.6 at%, respectively, at 4.2 K under an applied field of 90×79.6 kA·m-1. The MR value is decreased with increasing Co content, which can be attributed to the evolution of microstructure.

关 键 词：CO含量 Co-C纳米复合薄膜 磁性能 磁电阻 

分 类 号：TB383.2[一般工业技术—材料科学与工程]