Crossover from Efros-Shklovskii to Mott Variable Range Hopping in Amorphous Thin NixSi(subscript 1-x) Films

10.6122/CJP.52.251

M. Errai；A. El kaaouachi；A. Narjis；C. T. Liang；L. Limouny；S. Dlimi；A. Sybous

Chinese Journal of Physics

52卷1期PartI（2014 / 02 / 01）

251 - 261

英文

The temperature dependence of the electrical conductivity of insulating amorphous Ni(subscript x)Si(subscript 1-x) alloys is studied in the temperature range 1-160 K. At low temperatures, Efros-Shklovskii (ES) variable range hopping (VRH) is observed. This is assumed to occur because of the creation of the Coulomb gap (CG) in the vicinity of the Fermi level. With increasing temperature, the CG vanishes and the measured conductivity can be described by the Mott VRH model, where the density of states is constant. The criterion of the crossover ES from to Mott VRH is assessed by extracting the related parameters.