Origin of negative magnetoresistance in polycrystalline SnO 2 films

Recently observed quantum corrections to the conductivity of SnO 2 films suggest the existence of extended states and thus raise the question about the presence and mechanism of a metal-insulator transition. We present a comparative analysis of negative magnetoresistance, observed in fields up to 52 T on SnO 2 polycrystalline films, performed in the frame of both hopping conduction model and quantum corrections to the conductivity model, with the purpose to establish the ranges of agreement between these models and the obtained data. Our results suggest that the observed negative magnetoresistance of SnO 2 films is due to corrections stemming from the weak localization and electron-electron interaction.