Band engineering magneto-resistance effect in Co:a-C films. (January 2015)

• Record Type: Journal Article
• Authors: Chuang, P.Y.; Huang, J.C.A.; Lu, P.E.; Hsu, H.S.; Sun, S.J.; Yang, Y.W.; Chen, J.M.; Lee, C.H.
• Is Part Of: Carbon. Volume 81(2015)
• Page Start: 821
• Page End: 825
• Publication Date: 2015-01
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2014.10.032
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Co-doped amorphous carbon (Co: a -C) films, which comprise a homogeneously mixed carbon matrix phase with approximately 5 at.% cobalt, were deposited on quartz glass by radio frequency magnetron sputtering. A bias-dependent positive magnetoresistance (PMR) with a peak at a particular voltage was observed. The electronic structures were examined by ultraviolet photoelectron spectroscopy and X-ray absorption near edge spectroscopy. The spectroscopic results reveal that Co doping promotes the graphitization in the a -C matrix and the 3d orbital of Co is hybridized with sp 2 states (DOSs) in the Co: a -C. The PMR effect is related to the modulation of the DOS of the Co: a -C films at the Fermi level by Zeeman splitting.