Bi-rich sodium-phosphate glass: investigation of optical properties and the formation of elemental bismuth nanoparticles

Abstract

Nanoparticulate materials show different physical-chemical behavior com-pared with their respective bulk, such as gold nanoparticles could exhibiting a range of absorption wavelength depending on their particle size and shape. Moreover, metallic and nonmet-allic nanoparticles may present the effect of surface plasmon resonance (SPR) when their delocalized electrons oscillate in resonance with the electric field of a specific wavelength, varying according to their size and shape. Among nanoparticles in glass, bismuth nano-particles are difficult to obtain since bismuth can assume many oxidized states, Bi+, Bi2+, Bi3+, and Bi5+, depending on the synthesis conditions (melting tempera-tures, the crucible, cooling rate) and glass composition. Bismuth nanoparticles show in-teresting optical properties promising for photonic applications, such as large optical nonlinearity, fluorescence and visible absorption. Elemental bismuth nanoparticles could be obtained by using reducing conditions (reagents, crucible and/or atmosphere), or by thermal dissociation at high temperatures. The bismuth-based glass looks different col-ors, from yellowish to brownish, assigned to the presence of different bismuth species. Therefore, this proposal has the main object of the study and better understanding the optical properties of the Bi-rich phosphate glass system and also the influence of the melting-quetching synthesis method on the formation of Bi0 nanoparticles. (AU)