Articles written in Bulletin of Materials Science
Volume 30 Issue 4 August 2007 pp 333-338 Electrical Properties
The present study focuses on critical factors limiting single-phase formation of Ba2Ti9O20 (2 : 9). Apart from 2 : 9, other polytitanates that are richer in Ti or Ba could also be prepared as single-phase material without any stabilizing agent through chemical co-precipitation. 2 : 9 is found to be a stoichiometric compound and even 0.5% excess Ti or Ba leads to multiphase formation. Single-phase 2 : 9 could be achieved even through solid-state route without the addition of stabilizing agents using high purity raw materials. The present results do not agree with existing hypotheses viz. diffusion, high surface and nucleation energy, potential barrier, non-stoichiometry etc as critical factors limiting formation of 2 : 9 as single-phase material.
Volume 39 Issue 1 February 2016 pp 27-33
Pure and Nd3+-doped tin oxide (SnO2) nanoparticles have been prepared by the sol–gel method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM, energydispersive spectroscopy and UV–visible spectroscopy. The XRD patterns of all the samples are identified as tetragonal rutile-type SnO2 phase which is further confirmed by TEM analysis. Neodymium doping introduces band gap narrowing in the prepared samples and enhances their absorption towards the visible-light region. The photocatalytic activity of all the samples was evaluated by monitoring the degradation of methylene blue solution under day light illumination and it was found that the photocatalytic activity significantly increases for the samples calcined at 600 than 400°C, which is due to the effective charge separation of photogenerated electron–hole pairs. The efficiency of photocatalysts was found to be related to neodymium doping percentage and calcination temperature.
Volume 42 | Issue 6
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