title: Low temperature magnetoresistance measurements on bismuth nanowire arrays.
abstract: We present low temperature resistance R(T) and magnetoresistance measurements for Bi nanowires with diameters between 100 and 500 nm, which are close to being single-crystalline. The nanowires were fabricated by electrochemical deposition in pores of polycarbonate membranes. R(T) varies as T(2) in the low temperature range 1.5 K<T<10 K and exhibits a maximum which shifts from 140 to 250 K with decreasing wire diameter. An unexpected effect is observed in R(T) when a magnetic field is present. It can be related to the temperature dependence of the magnetoresistance. The transverse magnetoresistance of all samples shows a clear B(1.5) variation. Its size depends strongly on the diameter of the wires but only weakly on temperature. Finally, a steplike increase in the magnetoresistance of our sample with a wire diameter of 100 nm was found and this might be attributed to a transition from one-dimensional to three-dimensional localization.
authors.affiliation: Physikalisches Institut, Universität Karlsruhe, D-76128 Karlsruhe, Germany.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Kaiser
authors.forename: G
authors.initials: G
authors.lastname: Weiss
authors.forename: T W
authors.initials: TW
authors.lastname: Cornelius
authors.forename: M E
authors.initials: ME
authors.lastname: Toimil-Molares
authors.forename: R
authors.initials: R
authors.lastname: Neumann