Crystal Orientation and Transport Properties of a 633-nm-Diameter Bismuth Nanowire

Abstract

The crystal orientation and resistivity of a bismuth nanowire (diameter 633 nm, length 1.91 mm) encased in quartz were measured. The nanowire surface was irradiated with a high-intensity, collimated x-ray beam through the quartz template, and several Laue spots were observed with no streak patterns. Therefore, we concluded that the nanowire was a single crystal. The crystal orientation could be determined by measuring the relationship between the Laue spot distribution and the location of the nanowire fixed by a goniometer. The direction along the wire length was strongly directed toward the bisectrix axis of bismuth. The temperature dependence of the nanowire resistivity was measured; the resistivity at 300 K was 1.40 μΩ m, which is somewhat greater than that of the bulk sample due to the lower mobility of the nanowire. The temperature coefficient of resistivity was positive in the temperature range from 300 K to 165 K, and it became negative below 165 K. The temperature dependence can be modeled by accounting for the limited electron mean free path in the bismuth nanowire based on the crystal orientation determined by the Laue measurements.