Effects on the polarizability of mesoscopic metallic nanoparticles

The effects of temperature variation on the electric polarizability of mesoscopic metallic nanoparticles is studied via a theoretical model in which the temperature dependence of the electron–phonon and electron–electron scattering rates are taken into account. Furthermore, the nonlocal response of the metal, which is significant for particles of mesoscopic dimensions, is also included. It is found that the significance of the nonlocal effects can be very different with different metals, for the same smallness in size of the nanoparticles. In addition, while the imaginary part of the polarizability in general increases with temperature, the real part can both decrease or increase as temperature rises—in contrast to the case with the static polarizability of atomic clusters, which most of the time increases with temperature.