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Appl. Phys. Lett., Vol. 73, No. 10, 7 September 1998
Liu et al.
for sensing at very low fields. Preliminary results with the
incorporation of field concentrators into the nanowire struc-
ture have shown encouraging improvement on the field sen-
sitivity. Finally, because of the nanowire geometry, field
sensing is administered locally near the tip of the nanowire.
This suggests the possibility of using Bi nanowire arrays
with a controlled wire density as massive parallel-sensing
systems in high-density perpendicular recording media, such
as those of quantum disks.21
In summary, we have successfully fabricated arrays of
semimetallic Bi nanowires using electrodeposition. Very
large positive magnetoresistance, 300% at low temperatures
and 70% at room temperature, with quasilinear field depen-
dence have been observed. The one-dimensional nanostruc-
tures of semimetals show promise of a new medium for fruit-
ful explorations of interesting phenomena and technological
applications.
This work is supported by NSF MRSEC Program No.
96-32526.
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