Nonlinear optical properties and stability of Ag/Pt bimetallic nanoparticles in α − Al2O3

Abstract

Metallic nanoparticles are well known to have interesting optical properties. However, a good understanding of those properties still needs to be added in order to be able to control them entirely for future optoelectronic applications. Metallic nanoparticles are still more promising but must be understood because further parameters play essential roles in their formation and transformations. In this paper, we present the results of measurements of the nonlinear optical absorption and refractive index of an oversaturated solid solution of Ag and Pt in α − Al₂O₃, as well as of Ag₁₅Pt₁₇ alloyed nanoparticles and Pt-Ag core–shell nanoparticles. Our results indicate that at high irradiance levels, the two former configurations transform into the latter one during the measurements.