Carbon nanotubes with junctions are considered to be of potential value in
nanoelectronics. A simple pyrolysis procedure for producing Y-junction carb
on nanotubes is described. The method involves the pyrolysis of the organom
etallic precursor, nickelocene, along with thiophene at 1273 K. Tunneling c
onductance measurements showed that at the Y junction, the I-V characterist
ics are asymmetric with respect to zero bias as in a junction diode. (C) 20
00 American Institute of Physics. [S0003-6951(00)04942-1].