Templated Photonic Crystal Fabrication of Stoichiometrically Complex Nanoparticles for Resonance Raman Solid Cross Section Determinations

Development of methods to fabricate nanoparticles is of great interest for many applications. In this paper, we developed a facile method to fabricate complex stoichiometrically defined nanoparticles by ultilizing the defined volume 1 interstices of dose-packed photonic crystals. Fabrication of small defined size nanoparticles enables measurements of resonance Raman cross sections of solid materials. We successfully ultilized this method to fabricate mixed NaNO(3)/Na(2)SO(4) nanoparticles with a defined stoichiometry on the surface of the photonic crystal spherical particles. We used these stoichiometrically defined NaNO(3)/Na(2)SO(4) nanoparticles to determine the solid UV resonance Raman cross section of the NO(3)(-) nu 1 symmetric stretching band (229 nm excitation wavelength) by monitoring the Raman spectrum of Na(2)SO(4) as an internal standard. These are the first resonance Raman cross section measurements of solids that avoid the biasing of self-absorption. These NaNO(3)/Na(2)SO(4) nanoparticles appear to show a more facile photolysis than is observed for normal solid NaNO(3) samples. This templated photonic crystal fabrication of complex nanoparticle method will be important for many applications.