Temperature dependence of resistance and magnetoresistance of nanogranular Co-Ag films

We report a number of unusual features in the temperature dependence of the resistance and the magnetoresistance of nanogranular Co-Ag films at low temperatures. These include a nonmonotonic temperature dependence of the resistance in a nonmagnetized state, anomalously low exponents in the power-law temperature dependence of the resistivity (down to $\rho \propto T^{1.1})$ at high magnetic field, and almost linear temperature dependence of the giant magnetoresistance with no saturation at low temperature.