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采用直流磁控溅射技术,在n-Si(100)衬底上制备了Cox C100-x(x=2.5～50,at%)颗粒膜,并对薄膜的结构、形貌、磁性能和巨磁电阻(GMR)效应做了系统的研究。结果表明:制备态的Co-C薄膜为非晶结构,且表面光滑、颗粒尺寸及膜厚度均匀;随热处理温度的增加,Co成分在300℃逐渐开始晶化,400℃基本晶化完全,500℃度的时候膜层开始出现裂纹;拉曼光谱显示制备态薄膜为类金刚石(DLC)薄膜;X射线光电子能谱(XPS)分析表明,包埋在碳基薄膜中的Co掺杂纳米颗粒以单质形态存在,没有Co的碳化物出现,且Co掺杂没有促进碳膜的石墨化,Co-C纳米复合薄膜组成了一个互不相溶的金属/绝缘体体系;磁性能测试显示薄膜的饱和磁化强度(Ms)和矫顽力(Hc)与Co的含量和颗粒的晶化程度有密切关系;磁电阻测量结果表明Co2.5C97.5薄膜具有高达36%的正GMR效应,GMR效应遵循输运通道的转变机制。
The Cox C100-x (x = 2.5-50, at%) granular films were prepared on n-Si (100) substrates by DC magnetron sputtering. The structure, morphology, Magnetoresistance (GMR) effect of a systematic study. The results show that the as-prepared Co-C thin films have an amorphous structure with a smooth surface and a uniform grain size and film thickness. With the increase of the heat treatment temperature, the Co composition gradually begins to crystallize at 300 ℃. ℃, the cracks began to appear in the film; Raman spectroscopy showed that the as-prepared film was diamond-like carbon (DLC); X-ray photoelectron spectroscopy (XPS) analysis showed that Co-doped nanoparticles embedded in carbon- In the absence of Co carbides, Co-doping did not promote the graphitization of the carbon films. The Co-C nanocomposite films formed a mutually incompatible metal / insulator system. The magnetic properties of the films showed that the saturation magnetization The strength (Ms) and coercive force (Hc) are closely related to the content of Co and the degree of crystallization of the particles. The measurement results of magnetoresistance show that the Co2.5C97.5 film has a positive GMR effect of up to 36% and the GMR effect follows the transport Channel transition mechanism.