Simple one-step ion exchange enhanced Faraday rotation in heavy metal oxide diamagnetic glasses

Abstract Ion exchanges (IE) on silicate, tellurite, borate and phosphate glass have been extensively studied for different objectives such as changing glass refractive index, strengthening glass structure or realizing nanometal-glass systems, however, ion exchange on lead-bismuth-borate diamagnetic glass for Faraday rotation improvement is interesting and attractive for magneto optical glass and magneto optical waveguide devices. In this study, for the first time, we studied the one-step Ag+-Na+ ion exchange on diamagnetic Bi2O3-PbO-B2O3-Na2O (PBBN) glass for the aim of improving diamagnetic properties and providing an efficient route for magneto-optical waveguide. The Ag+-Na+ ions has been sucessfully exchanged at 270 °C for 20 min condition. And without any further heat or H2 treatment after IE, the Ag+ ions and Ag0 nanoparticles co-existed in glass. Heat treatment in H2 after IE not only greatly increased the Ag0 NPs size, but also produced the Bi0 crystals which were not helpful for glass properties. Ag nanoparticles showed characteristic surface plasmon resonance peak at 500–550 nm range. Raman spectra displayed the evolutions of Ag+ and Ag0 in functions of different ion exchange conditions. The UV–Visible and Faraday rotation measurements suggested that high polarizability and diamagnetic susceptibility properties of diamagnetic Ag+ ions and Ag0 nanoparticle induced surface plasmonic effects improved the optical refractive index and magneto optical Verdet constant. A simple linear optical waveguide also were obtained on PBBN glass surface using the optimized IE parameters. The proposed one-step ion exchange technique on diamagnetic glass will be an efficient method for glass properties enhancement and magneto optical waveguide fabrication.