| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1237197 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2010 | 7 Pages |
Dichroic Sm3+: Au-antimony glass nanocomposites are synthesized in a new reducing glass (dielectric) matrix (mol%) K2O–B2O3–Sb2O3 (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 Au0 nanoparticles are grown along the (2 0 0) plane direction. The transmission electron microscopic (TEM) image reveals the elliptical Au0 nanoparticles having major axis range 12–17 nm. Dichroic behavior is due to elliptical shape of Au0 nanoparticles of aspect ratio ∼1.2. Au0 NPs of concentration of 0.03 wt% (4.1 × 1018 atoms/cm3) drastically enhances the intensity (∼7-folds) of electric dipole 4G5/2 → 6H9/2 red transition (636 nm) of Sm3+ ions and then attenuates with further increase in Au0 concentration. The magnetic dipole 4G5/2 → 6H5/2 green (566 nm) and 4G5/2 → 6H7/2 orange (602 nm) transitions remain almost unaffected by presence of nano Au0. Local field enhancement (LFE) induced by Au0 SPR and energy transfer (ET) from fluorescent Au0 → Sm3+ ions are found to be responsible for the enhancement while reverse ET from Sm3+ → Au0 and optical re-absorption due to Au0 SPR for attenuation.
