摘要

We study the transport properties of C1-xCox thin films (with x = 0.1, 0.15 and 0.2) grown on Si substrate by pulsed laser deposition technique. The results demonstrate some anomalous effects in the behavior of the measured resistance R(T,x). More specifically, for 0 < T< T* range (with T* similar or equal to 220 K) the resistance is shown to be well fitted by a small polaron hopping scenario with R-h(T,x) proportional to exp{[T-0(x)/T](0.5)} and a characteristic temperature T-0(x) similar or equal to T-0(0)(1 - x) (with T-0(0) = 120 K). While for higher temperatures T* <T < T-C(x), the resistance is found to be linearly dependent on spontaneous magnetization M(T,x), viz. R-M(T,x)proportional to M(T,x), following the pattern dictated by electron scattering on cobalt atoms formed robust ferromagnetic structure with the Curie temperature T-C(x) obeying a percolation like law T-C(x)similar or equal to T-C(x(m))(x/x(m))(0.15) with T-C(x(m)) = 295 K and the maximum zero-temperature magnetization reaching M(0, x(m))=0.5 mu(B) per Co atom for x(m) = 0.2.

  • 出版日期2016-5-15
  • 单位Univ Estadual Paulista