AFM microscopy and optical studies for the shape of particles in ultrathin silver films

作者：Bolesta I M^*; Kushnir O O

来源：Ukrainian Journal of Physical Optics, 2012, 13(3): 165-170.

• ultrathin silver films
• absorption spectra
• surface plasmon resonance
• AFM topology

This work deals with investigations of AFM morphology and optical absorption spectra of ultrathin silver films with the mass thicknesses 0.7-1.4 nm. It is shown that the main structural elements of our Ag films are metallic clusters with the shapes of spheroids. The root mean square height and the correlation length of the film surfaces are determined using correlation analysis. The absorption spectra of the films reveal a characteristic complex band in the region of 400-500 nm, which is associated with the transversal and longitudinal oscillations of surface plasmons. In the framework of the quasi-static approximation, the splitting Delta E of the surface plasmonic bands is calculated as a function of ratio c/a for the spheroids. A comparison of Delta E values obtained experimentally with the calculated ones allows for estimating the c/a ratio for the spheroidal clusters, following from the optical spectra. This estimation agrees well with the AFM data.

• 出版日期2012-9