• R Bhat

      Articles written in Bulletin of Materials Science

    • Alumina ceramics by sol-gel technique

      S Ramanathan R Bhat D D Upadhyaya S K Roy

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      The processing of alumina ceramics using the sol-gel technique was investigated. Alumina sols were prepared by precipitation-peptization of aluminium hydroxide obtained from aluminium nitrate and aluminium oxyhydroxide obtained from aluminium isopropoxide. Sols cast on Teflon substrate were gelled by controlled dehydration at near-ambient temperature. Gels were converted to ceramics through processes of drying, calcination and sintering in the temperature range 773–1473 K. Ceramics derived from both the sols retained a porosity of 35–45% even after sintering at 1273 K. However, at 1473 K densification was drastically enhanced and bodies could be sintered to about 90–93% of theoretical density (TD) and was accompanied by theϑ-to-α transformation. The progress of the reactions occurring at various stages of the process was studied using pycnometry, TG-DSC, XRD, SEM, MIP and TEM techniques.

    • Synthesis, characterization and optical absorption studies of Na[Fe(CN)$_4$(C$_3$H$_4$N$_2$)NO]2H$_2$O crystals

      MOHD HANIEF NAJAR WASEEM GULZAR NAKASH SYED KAZIM MOOSVI AJMAL R BHAT KOWSAR MAJID

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      Crystals of Na[Fe(CN)$_4$(C$_3$H$_4$N$_2$)NO]2H$_2$O (SNP-d) have been prepared by photochemical route using sodium nitroprusside (SNP) as precursor complex. The crystals were subjected to various characterization techniques such as energy dispersive X-ray analysis, Fourier transform infrared, UV–visible spectroscopy and X-ray diffraction. From X-ray diffraction, it has been observed that SNP-d belongs to orthorhombic crystal system with primitive lattice. Crystallite size has been found to be 79.2 nm. Molecular structure of SNP-d depicts its non-centrosymmetric nature. As observed from UV–visible spectroscopy, SNP-d crystals form a double bandgap material, between which transitions have been found to be direct allowed. High value of refractive index and low value of reflectance, as obtained from Reddy, Anjaneyulu and Fresnel’s equations, indicate transparency of material to visible radiation. This is clearly justified from UV–visible spectra as the wavelength cutoff is around 300 nm.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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