The influence of the shape of a sample on the type of uniform dipole collective electrons oscillations is discussed. In samples of a bulk shape uniform bulk dipole oscillation (Langmuir oscillation) cannot exist. It exists in samples of a thin slab shape only. As uniform bulk dipole oscillations cannot penetrate ellipsoidal samples of conductive material, they exist in the surface layer of a sample only (Mie oscillations). Frequencies of Mie oscillations are alculated for a sample of the shape of an arbitrary ellipsoid.
Categories: cond-mat.mtrl-sci physics.plasm-ph