MAGNETOTRANSPORT INVESTIGATIONS OF ULTRAFINE SINGLE-CRYSTALLINE BISMUTH NANOWIRE ARRAYS

We have measured the magnetotransport properties of ultrafine single-c rystalline Bi nanowire arrays embedded in a dielectric matrix. At low temperatures (T less than or equal to 50 K), the wire boundary scatter ing is shown to be the dominant scattering process for carriers. A rev ersal in the temperature dependence of the magnetoresistance was obser ved for wires with 65 nm average diameter relative to those with 109 n m average diameter when T less than or equal to 100 K. We attribute th is difference to effects due to the quantization of the transverse mom entum of the carriers, which results in a semimetal-semiconductor tran sition for Bi nanowires as the wire diameter becomes sufficiently smal l. (C) 1998 American Institute of Physics.