We report on the electrical resistance and time‐dependent oxidation of thin (≲90 A˚) semicontinuous bismuth films. An increase in the room temperature sheet resistance with exposure to air is correlated with the growth of insulating Bi2O3at the surfaces and internal boundaries between bismuth particles. For short oxidation timest, the resistance increases asRlaplac;∝t1/2, consistent with a parabolic oxide growth law. At longer times the resistance follows the classical percolation lawRlaplac;∝‖tc−t‖−mgr;, wheretcis a critical exposure time and mgr;bartil;1.3 is a critical exponent for two‐dimensional systems.
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