Optical properties of sol–gel fabricated Mn/SiO2 nanocomposites: Observation of surface plasmon resonance in Mn nanoparticles

Abstract Manganese nanoparticles were grown in silica glass and silica film on silicon substrate by annealing of the sol–gel prepared porous silicate matrices doped with manganese nitrate. Annealing of doped porous silicate matrices was performed at various conditions that allowed to obtain the nanocomposite glasses with various content of metallic Mn. TEM of Mn/SiO 2 glass indicates the bimodal size distribution of Mn nanoparticles with mean sizes of 10.5 nm and 21 nm. The absorption and photoluminescence spectra of Mn/SiO 2 glasses were measured. In the absorption spectra at 300 nm (4.13 eV) we observed the band attributed to the surface plasmon resonance in Mn nanoparticles. The spectra proved the creation of Mn 2+ and Mn 3+ ions in silica glass as well. The absorption spectra of Mn/SiO 2 glasses annealed in air prove the creation of manganese oxide Mn 2 O 3 . The measured reflection spectra of Mn/SiO 2 film manifest at 240–310 nm the peculiarity attributed to surface plasmons in Mn nanoparticles.