Strong Temperature Dependence of Magnetoresistance in Co-C Granular Thin Films

Author

Tang, Ruihe ; Mizuguchi, Masaki ; Wang, Hai ; Yu, Ronghai ; Takanashi, Koki

Author_Institution

Inst. for Mater. Res., Tohoku Univ., Sendai, Japan

Volume

46

Issue

6

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

2144

Lastpage

2147

Abstract

Co-C granular thin films with a Co content of 6.4 at.% were deposited at room temperature by co-sputtering. The magnetotransport properties of the thin films were investigated within 2-300 K under magnetic fields up to 90 kOe. A large negative magnetoresistance (MR) of 27.6% was successfully observed at 2 K. As temperature (T) increased, negative MR decreased drastically. Meanwhile, positive MR with an organic MR (OMAR)-like shape emerged in a low magnetic field region. Ordinary MR (OMR) appeared in a high magnetic field region and can be verified by MR Â¿ H² fitting. When T reached 10 K, MR became completely positive. The MR effect showed strong temperature dependence. The interesting phenomena may help us gain a new insight into the spin-dependent transport in ferromagnetic metal (FM)/amorphous-carbon (Â¿-C) system.

Keywords

carbon; cobalt; ferromagnetic materials; granular materials; magnetic thin films; magnetoresistance; spin polarised transport; sputtered coatings; Co-C; co-sputtering; ferromagnetic metal-amorphous carbon system; granular thin films; magnetotransport; negative magnetoresistance; spin-dependent transport; temperature 2 K to 300 K; temperature dependent magnetoresistance; Amorphous magnetic materials; Magnetic field measurement; Magnetic fields; Magnetic films; Magnetic materials; Magnetic properties; Ordinary magnetoresistance; Sputtering; Temperature dependence; Transistors; Magnetic granular thin film; temperature dependence of magnetoresistance; transport mechanism;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2010.2043340

Filename

5467514