This work was financially supported by the Ministry of Science and Technology of China (No. 2002CB613500) and National Natural Science Foundation of China (No. 50271034, No. 90401013).
Using pulsed laser deposition, Fex-C1-x films on Si (100) substrates were prepared. At T=300 K and B=5 T a large positive MR of 138% was found in Fe0.011-C0.989 film. It is also found that when T<258 K, the MR of Fe0....