| || Synthesis of Cobalt Oxide Nanoparticles/Fibres in Alcoholic Medium using gamma-ray Technique
Author : Athawale, Anjali A.;Majumdar, Megha;Singh, Hema;Navinkiran, K.
Source : Defence Science Journal ; Vol:60(5) ; 2010 ; pp 507-513
Subject : 53 Applied Physics;Defence Science Journal
Keywords : Oxides;X-ray diffraction;X-ray photoelectron spectroscopy;XPS;optical properties;gamma irradiation technique;magnetic nanoparticles;UV-visible spectroscopy;spectroscopy;cobalt-oxide nanoparticles;nanoparticle synthesis
Abstract : Nanoparticles of cobalt oxides were synthesised by steady state g irradiation technique using various alcoholic salt solutions of cobalt ions with aniline acting as a stabiliser. Preliminary results were investigated using UV-vis and Fourier transform infra red analysis. The X-ray diffractograms revealed major peaks at 2q values of ~ 36.4°, 39.1°, 44.2°, and 65.7° corresponding to the Co3O4 phase and one peak at ~30.7° (100 per cent intensity) for Co2O3 phase. Lower alcohols yielded particles while fibres were formed in higher alcohols as observed from transmission electron microscopic analysis. Iso-propanol was observed to yield cobalt oxide nanoparticles with highest stability, conversion yield and homogeneity in size. The average measured diameter and length of these fibres were ~29 nm and 130 nm respectively. Energy dispersive spectroscopy supports the formation of cobalt oxide. The X-ray photoelectron spectroscopic results for iso-propanol sample show a peak at 781.6 eV confirming the formation of Co3O4.
| || Studies in the ageing of cordites by X-ray diffraction
Author : Parihar, D.B. ;Chatterji, A.K.
Source : Defence Science Journal ; Vol:6(2) ; 1956 ; pp 108-115
Subject : 535.44 Diffraction Methods
Keywords : X-ray diffraction
Abstract : The results of X-ray diffraction on the ageing of WM & NA cordites, particular that of nitrocellulose, are reported. The samples studied were: (1) Relative fresh samples (1953) (2) Naturally aged samples(stored for about 10 years), (3) Accelerated ages ones(sample kept at 70degree C for 80 hours), (4) Samples kept at liquid air temperature for 5 hours, and (5) liquid air treated samples subjected to accelerated ageing (70 degree C for 80 hours). Two points are important about nitrocellulose: (1) denitration and (2) formation of microcrystallites. The 'd' value of the inner most arcs in WM and AN cordites considerably decreases on natural ageing. Similar change is observed in accelerated aged sample of WM, which is cooled to liquid air temperature.