Plasmon excitation modes in nanowire arrays

Electron energy loss spectrometry and energy-filtered transmission electron microscopy reveal characteristic plasmon excitations in both isolated Bi n anowires and an array of Bi nanowires within an Al2O3 matrix. As the averag e nanowire diameter decreases from 90 to 35 nm, both the volume plasmon ene rgy and peak width increase. In addition, a lower-energy excitation is pres ent in a very localized region at the Bi-Al2O3 interface. These results are discussed in the context of quantum confinement and the influence of inter faces on the electronic properties of nanocomposite materials. (C) 2001 Ame rican Institute of Physics.