Transverse magnetoresistance of uniaxially deformed thin polycrystalline n-Bi films

Abstract

Large influence of uniaxial stretch (strain) S and compression P on transverse and perpendicular resistivity ρρ and magnetoresistance (MR) of polycrystalline n-Bi lms was investigated. The calculations were performed on the basis of polycrystalline Bi thin film model and electron intervalley repopulation in deformed film crystallites. The calculations show that in n-Bi films the influence of P on ρρ can be many times larger because T-holes in Bi films significantly reduce the effect of deformation. It was found that S and P cause considerably different dependences of ρ and MR on magnetic field strength. The effect of P on the ρ and MR is of opposite sign as compared to S and can be larger than that of S. In strong non-quantizing magnetic field region the transverse ρ appears to be independent of deformation. The investigated high-quality 1.5 μm thick Bi films consisting of up to 200 μm length crystallites were deposited on non-crystalline substrate and annealed at critical temperature close to the film melting temperature. The experimental results confirm the theoretical predictions.
Keywords: bismuth, thin films, magnetoresistance, deformation
PACS: 68.55.-a, 73.50.Jt, 75.70.Ak