Magnetotransport properties of thin C–Fe films

The magnetotransport properties of C–Fe films formed by e-beam vapor deposition onto glass substrates are presented in the temperature region of 2 K to 300 K. Hall effect measurements reveal a significant anomalous Hall voltage whose magnitude increases with increasing temperature. Measurements of the ordinary Hall coefficient in 10 nm-thick films reveal a charge carrier density ranging from n ≅ 3.0 × 1029 m−3 at 2 K to approximately half that value at 290 K. A comparison between anomalous Hall effect and parallel field magneto-optic Kerr effect measurements reveals a highly anisotropic coercive field with the easy direction lying in the plane of the film. Magnetoresistance measurements show that the films posses isotropic linear positive magnetoresistance beyond their saturation magnetization. The presence of carbon nanotubes formed during the e-beam process is confirmed via atomic force microscopy.