Scaling of Hall coefficient in Co-Bi granular thin films

Abstract

A series of Co-Bi thin films with Co concentrations c=0, 0.05, 0.2, 0.26, 0.3, 0.333, 0.375, 0.545, were grown by magnetron sputtering on Si(100)/SiNX substrates. Resistivity measurements at zero field (ρxx) as a function of temperature-T exhibit an exponential variation with T in the region of 240K<T<300K. The Hall coefficient as a function of Co concentration diverges as log|c-0.3|0.3 for c<0.333, indicating a scaling of RH nearby a percolation threshold pc=0.3. Only after proper scaling of the anomalous Hall coefficient RS the conventional RS∝(ρxx)n dependence can be satisfied.