A new surface plasmon resonance in clusters of small aluminum spheres

Inelastic scattering of fast electrons in clusters of small aluminum spheres reveals a new surface plasmon mode near 4 eV. Electron energy loss filtered images show that the mode occurs within 10-40 nm spheres which touch other single spheres or clusters of spheres. The energy and spatial variations of the mode are consistent with a surface plasmon resonance at the metal-oxide-metal interface which is present at the point of contact between neighboring spheres. © 1982.