| || Synthesis of Nanocrystalline PZT by Hydrothermal Method
Author : Athawale, Anjali A.;Bapat, Malini S.
Source : Defence Science Journal ; Vol:57(1) ; 2007 ; pp 35-39
Subject : 66 Chemical Technology
Keywords : Lead zirconium titanate;Piezoelectric materials;Electrostrictive materials;Actuators;Memory alloys;PZT nanoparticles;Perovskite structure;Perovskite;Hydrothermal synthesis
Abstract : Synthesis of lead zirconium titanate by a simple, low-energy consumption hydrothermal means is being reported. The precursor materials have been chosen and the method is tailored so that the process becomes economical and offers low lead loss. The synthesised powders have been analysed by FTIR, XRD, SEM, TEM, and TGA. The results show the formation of tetragonal PZT nanoparticles with an average yield of ~75 per cent. On the basis of FTIR, the product formation is understood to proceed via the formation of a three metal cation hydroxide complex, that under hydrothermal treatment undergoes conversion directly to form the tetragonal phase of lead zirconium titanate.
| || 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.