Weak Localization and Electron-Electron Interactions theories applied to the positive magnetoresistance in metallic Si1-yNiy:H alloys

Electrical conductivity of hydrogenated amorphous silicon nickel alloys (Si1-yNiy:H) is discussed on the metallic side of the metal insulator transition (MIT), at very low temperature, and in the presence of magnetic field up to 4.5T. The experimental results are analyzed in the light of weak localization and electron-electron interaction theories in a strong spin-orbit case. The zero magnetic field conductivity is almost found to vary according to the formula σ(B=0,T)=σ0+m.T1/2. Physical interpretations of our results are given to understand the diffusion mechanism