An effect of internal structure of bimetallic nanoparticles on optical properties for AuAg/glass material

Optical extinction spectra calculated via multisphere $T$-matrices for nanoparticles with different concentrations of metals and different architectures (core–shell, inverse core–shell, or alloy) are considered. A method is proposed for determination of architecture of nanoparticles (core–shell or alloy) from only data on the position of plasmon resonance and composition of components. The use of an optical spectrum fitting technique to the spectra of monodisperse noninteracting bimetallic nanoparticles with a predetermined structure appeared to be effective for the determination of the internal structure of nanoparticles, except large nanoparticles with a radius of more than 60 nm containing less than $\sim$25% silver atoms.