title: Enhanced frequency upconversion of Sm3+ ions by elliptical Au nanoparticles in dichroic Sm3+: Au-antimony glass nanocomposites.
abstract: Dichroic Sm(3+): Au-antimony glass nanocomposites are synthesized in a new reducing glass (dielectric) matrix (mol%) K(2)O-B(2)O(3)-Sb(2)O(3) (KBS) by a single-step melt-quench technique involving selective thermochemical reduction. X-ray diffraction (XRD) and selected area electron diffraction (SAED) results indicate that Au(0) nanoparticles are grown along the (200) plane direction. The transmission electron microscopic (TEM) image reveals the elliptical Au(0) nanoparticles having major axis range 12-17 nm. Dichroic behavior is due to elliptical shape of Au(0) nanoparticles of aspect ratio approximately 1.2. Au(0) NPs of concentration of 0.03 wt% (4.1 x 10(18)atoms/cm(3)) drastically enhances the intensity ( approximately 7-folds) of electric dipole (4)G(5/2)-->(6)H(9/2) red transition (636 nm) of Sm(3+) ions and then attenuates with further increase in Au(0) concentration. The magnetic dipole (4)G(5/2)-->(6)H(5/2) green (566 nm) and (4)G(5/2)-->(6)H(7/2) orange (602 nm) transitions remain almost unaffected by presence of nano Au(0). Local field enhancement (LFE) induced by Au(0) SPR and energy transfer (ET) from fluorescent Au(0)-->Sm(3+) ions are found to be responsible for the enhancement while reverse ET from Sm(3+)-->Au(0) and optical re-absorption due to Au(0) SPR for attenuation.
authors.affiliation: Glass Technology Laboratory, Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research), 196 Raja SC Mullick Road, Kolkata 700 032, India.
authors.forename: Tirtha
authors.initials: T
authors.lastname: Som
authors.forename: Basudeb
authors.initials: B
authors.lastname: Karmakar
mesh_terms: D000965:Antimony; D018360:Crystallography, X-Ray; D005898:Glass / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry*; D012493:Samarium / Q000737:chemistry*
chemical_list: D012493:Samarium; D006046:Gold; D000965:Antimony