Large magnetoresistance in post-annealed polycrystalline and epitaxial Bi thin films

We have observed a large increase in the magnetoresistance (MR) of polycrystalline and epitaxial thin Bi films, which were subjected to a post-annealing procedure at 3°C below the Bi melting point. We have achieved an increase in the MR by a factor of 2560 at 5 K as compared with 343 for an as-grown epitaxial film due to enhanced carrier mobilities.