K Rajendra Babu
Articles written in Bulletin of Materials Science
Volume 24 Issue 2 April 2001 pp 249-252 Crystal Growth
Thermal behaviour of strontium tartrate single crystals grown in gel
M H Rahimkutty K Rajendra Babu K Sreedharan Pillai M R Sudarsana Kumar C M K Nair
Thermal behaviour of strontium tartrate crystals grown with the aid of sodium metasilicate gel is investigated using thermogravimetry (TG) and differential thermal analysis (DTA). Effect of magnetic field and dopant (Pb)2+ on the crystal stability is also studied using thermal analysis. This study reveals that water molecules are locked up in the lattice with different strengths in the grown crystals.
Volume 29 Issue 2 April 2006 pp 119-122 Ceramics and Glasses
Thermoluminescence dosimetry of rare earth doped calcium aluminate phosphors
K Madhukumar K Rajendra Babu K C Ajith Prasad J James T S Elias V Padmanabhan C M K Nair
The thermoluminescence (TL) properties of calcium aluminate (CaAl2O4) doped with different rare earth ions have been studied and their suitability for radiation dosimetry applications is discussed. It is observed that monocalcium aluminate doped with cerium is a good dosimeter having linear response up to about 4 kGy of radiation doses. Dopant concentration of 0.25 mol% cerium gives maximum TL emission. The well-defined single peak observed at 295°C can be advantageously used for high temperature dosimetry applications.
Volume 30 Issue 4 August 2007 pp 349-355 Single Crystals
B Suresh Kumar M H Rahim Kutty M R Sudarsana Kumar K Rajendra Babu
The effect of lithium ion as dopant on the size and transparency of strontium tartrate tetrahydrate (SrC4H4O6.4H2O) crystals are presented in this paper. Growth of single crystals of undoped and lithium doped strontium tartrate tetrahydrate by controlled diffusion of strontium nitrate into the gel charged with tartaric acid at room temperature are narrated. The lithium ion enhances the size and transparency of the doped crystals. The crystal structure of the compound was confirmed by X-ray diffractometry and dopant concentration with ICP–atomic emission spectrometer system. Thermal decomposition of the grown crystals is investigated by TGA and DTA studies. The FTIR spectra of pure and doped crystals are recorded and analysed. Kurtz powder technique has been used to test SHG efficiency of the crystals.
Volume 39 Issue 1 February 2016 pp 27-33
Dhanya Chandran Lakshmi S Nair S Balachandran K Rajendra Babu M Deepa
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.
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