Structural and optical tunability of metallodielectric composites with gradual shell growth
- Resource Type
- Original Paper
- Authors
- SHARMA, ANKITA; DHIMAN, NARESH; SINGH, B P; GATHANIA, ARVIND K
- Source
- Pramana: Published by the Indian Academy of Sciences. January 2016 86(1):147-155
- Subject
- Metallodielectric
composites
surface plasmon resonance
optical properties
78.67.Sc
81.05.Ni
73.20.Mf
- Language
- English
- ISSN
- 0304-4289
0973-7111
Metallodielectric (gold@silica) composites were prepared by seed and grow method. The dielectric microspheres (core material) of an average size of 400 nm were synthesized by sol–gel method and gold nanoparticles (AuNPs) were prepared by reducing the chloroauric solution. Shell growth around silica (SiO2) microspheres was carried out in a multistep layer-by-layer process. The synthesized composites were characterized using techniques such as field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and UV–Visible (UV–Vis) spectroscopy. FE-SEM and FTIR analyses have confirmed the functionalization of SiO2 surfaces with the amine terminal group along with the gold shell growth. XRD analysis has given an average crystallite size of 12.3 nm for metallodielectric composites. Absorption spectra have demonstrated the dependence of surface plasmon resonance (SPR) peak on the successive shell growth by exhibiting a red shift.