Structure and giant magnetoresistance of carbon-based amorphous films prepared by magnetron sputtering
Structure and giant magnetoresistance of carbon-based amorphous films prepared by magnetron sputtering
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磁控溅射碳基非晶薄膜的结构与巨磁阻
DOI：
10.1016/j.tsf.2014.01.048
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发表时间：
2014-04-01
期刊：
影响因子：
2.1
通讯作者：
Cheng, G.
中科院分区：
文献类型：
--
作者：
Ma, L.;He, M. F.;Cheng, G.
采用直流磁控溅射技术在n-Si(100)衬底上制备了纯非晶碳(a-C)和Co掺杂CoxC1-x薄膜。在Co-C薄膜中，纳米尺寸的非晶Co颗粒均匀分散在非晶交联碳基体中。通过X射线光电子能谱和拉曼光谱研究了a-C和CoxC1-x薄膜的结构。结果表明a-C薄膜为类金刚石碳(DLC)薄膜。 DLC薄膜中掺杂钴后，DLC复合薄膜中sp(3)杂化碳含量几乎没有变化。沉积态CoxC1-x颗粒膜比非晶碳膜具有更大的磁阻(MR)值。当外部磁场垂直于电流和薄膜表面时，在室温下厚度为 80 nm 的 CoxC1-x 颗粒薄膜中观察到非常高的正 MR，在磁场 B = 0.8 T 和 x = 2.5 at.% 时高达 15.5%。随着薄膜厚度和Co掺杂量的增加，MR逐渐降低。很好地解释 CoxC1-x 颗粒膜中观察到的 MR 效应仍然是一个挑战。 (C) 2014 Elsevier B.V. 保留所有权利。
Pure amorphous carbon (a-C) and Co-doped CoxC1 - x films were prepared on n-Si(100) substrates by dc magnetron sputtering. In Co-C films, the nano-sized amorphous Co particles were homogeneously dispersed in the amorphous cross-linked carbon matrix. The structures of a-C and CoxC1 - x films were investigated by X-ray photoelectron spectroscopy and Raman spectroscopy. The results showed that the a-C films were diamond-like carbon (DLC) films. After doping cobalt into DLC film, the sp(3)-hybridized carbon content in DLC composite films almost had no change. The as-deposited CoxC1 - x granular films had larger value of magnetoresistance (MR) than the amorphous carbon film. A very high positive MR, up to 15.5% at magnetic field B = 0.8 T and x = 2.5 at.% was observed in a CoxC1 - x granular film with thickness of 80 nm at room temperature when the external magnetic field was perpendicular to the electric current and the film surface. With increase of the film thickness and Co-doped content, the MR decreased gradually. It remains a challenge to well explain the observed MR effect in the CoxC1 - x granular films. (C) 2014 Elsevier B.V. All rights reserved.