• S M Dharmaprakash

      Articles written in Bulletin of Materials Science

    • Studies on etching of gel-grown barium oxalate dihydrate crystals

      S M Dharmaprakash P Mohan Rao

      More Details Abstract Fulltext PDF

      Etch pits produced by selective etchants such as 1 M HCl, 1 M HNO3, 4 M BaCl2, 4 M NH4Cl and 4 M NH4Cl-1 M HCl solutions on the as-grown {110} faces of barium oxalate dihydrate crystals are illustrated and explained. The kinetics of etching is studied. From Arrhenius plots, the activation energy of etching and the pre-exponential factor are computed. An empirical equation governing the kinetics has been suggested.

    • Thermal properties of barium-cadmium oxalate crystals

      S M Dharmaprakash P Mohan Rao

      More Details Abstract Fulltext PDF

      The kinetics and thermodynamics of the thermal dehydration of crystalline powders of BaC2O4·2H2O, CdC2O4·3H2O and Ba1−xCdxC2O4·2·5H2O have been studied by means of thermogravimetry, as a function of temperature. The dynamic dehydration kinetics are also examined using DTA, recorded simultaneously with TG as a function of temperature. The validity of the estimated mechanism and kinetic parameters is briefly discussed. From DTA study it is concluded that all dehydration peaks are endothermic and the decomposition peaks of barium oxalate to barium carbonate, cadmium oxalate to cadmium oxide and barium cadmium oxalate to barium carbonate and cadmium oxide are exothermic.

    • Physico-chemical characterization of BaHPO4 crystals

      K C Hebbar S M Dharmaprakash P Mohan Rao

      More Details Abstract Fulltext PDF

      Characterization of the gel-grown barium hydrogen phosphate (BHP) crystals was performed by utilizing the techniques of chemical analysis, X-ray diffraction, infrared and thermal behaviour. The results show that BHP crystals had chemical composition BaHPO4 at room temperature. TG and DTA studies revealed the BHP crystals to be anhydrous at room temperature and decomposed at temperatures above 370°C and the decomposition was an endothermic process. Magnetic susceptibility measurements indicate the material to be diamagnetic.

    • Optical and structural characteristics of strontium doped calcium tartrate crystals

      K Suryanarayana S M Dharmaprakash K Sooryanarayana

      More Details Abstract Fulltext PDF

      We report here on the optical and structural characteristics carried out on strontium doped calcium tartrate tetrahedral single crystalline materials obtained by diffusing calcium and strontium ions through silica gel impregnated with optically active tartaric acid. Linear optical properties of this material such as refractive index, birefringence and transmission characteristics were measured in the wavelength range 200 nm <λ<1500 nm. No dispersion of the birefringence was observed within the experimental accuracy. The packing of tartrate molecules remained unaltered with 12% of the strontium doping.

  • Bulletin of Materials Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.