Articles written in Bulletin of Materials Science
Volume 33 Issue 3 June 2010 pp 251-255 Polymers
Effect of substrate roughness on growth of diamond by hot filament CVD
Awadesh K Mallik S R Binu L N Satapathy Chandrabhas Narayana Md Motin Seikh S A Shivashankar S K Biswas
Polycrystalline diamond coatings are grown on Si (100) substrate by hot filament CVD technique. We investigate here the effect of substrate roughening on the substrate temperature and methane concentration required to maintain high quality, high growth rate and faceted morphology of the diamond coatings. It has been shown that as we increase the substrate roughness from 0.05 𝜇m to 0.91 𝜇m (centre line average or CLA) there is enhancement in deposited film quality (Raman peak intensity ratio of 𝑠𝑝3 to non-𝑠𝑝3 content increases from 1.65 to 7.13) and the substrate temperature can be brought down to 640°C without any additional substrate heating. The coatings grown at adverse conditions for 𝑠𝑝3 deposition has cauliflower morphology with nanocrystalline grains and coatings grown under favourable 𝑠𝑝3 condition gives clear faceted grains.
Volume 34 Issue 2 April 2011 pp 207-216
Metal-coated magnetic nanoparticles for surface enhanced Raman scattering studies
G V Pavan Kumar N Rangarajan B Sonia P Deepika Nashiour Rohman Chandrabhas Narayana
We report the optimization and usage of surfactantless, water dispersible Ag and Au-coated 𝛾 –Fe2O3 nanoparticles for applications in surface-enhanced Raman scattering (SERS). These nanoparticles, with plasmonic as well as super paramagnetic properties exhibit Raman enhancement factors of the order of 106 (105) for Ag (Au) coating, which are on par with the conventional Ag and Au nanoparticles. Raman markers like 2-naphthalenethiol, rhodamine-B and rhodamine-6G have been adsorbed to these nanoparticles and tested for nonresonant SERS at low concentrations. Further, to confirm the robustness of Ag-coated nanoparticles, we have performed temperaturedependent SERS in the temperature range of 77–473 K. The adsorbed molecules exhibit stable SERS spectra except at temperatures >323 K, where the thermal desorption of test molecule (naphthalenethiol) were evident. The magnetic properties of these nanoparticles combined with SERS provide a wide range of applications.
Volume 46, 2023
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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