• R Vijayaraghavan

      Articles written in Bulletin of Materials Science

    • Low temperature synthesis of Ba1–𝑥Sr𝑥SnO3 (𝑥 = 0–1) from molten alkali hydroxide flux

      B Ramdas R Vijayaraghavan

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      Perovskite structured stannates (Ba1–𝑥Sr𝑥SnO3, 𝑥 = 0.0–1.0) powders have been synthesized for the first time by molten salt synthesis (MSS) method using KOH as the flux at lower temperature (400°C) compared to other methods. The phase formation was confirmed by FT–IR spectroscopy, powder X-ray diffraction (XRD) and the microstructure was analysed by scanning electron microscopy. XRD patterns reveal the formation of single phasic products for parent and substituted products with good crystallinity throughout the range (𝑥 = 0.0–1.0). The morphology of the particles of BaSnO3 and SrSnO3 is spherical and rod shaped, respectively. Effect of soaking periods on the grain growth is observed clearly in SrSnO3. Ba0.5Sr0.5SnO3 (BSS5) crystallizes in flake like morphology.

    • Detection of methane using multi-walled carbon nanotubes

      J Kathirvelan R Vijayaraghavan

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      A sensor for detecting and estimating methane using multi-walled carbon nanotubes (MWCNTs) as the sensing element has been developed for the first time. Silver electrodes have been ink-jet printed on glass substrate over which MWCNT is brush coated to fabricate the sensor element which is of chemoresistive type. The sensitivity of the sensor (increase in the resistance of the sensor on exposure to analyte) increases linearly with concentration of methane and a maximum sensitivity of about 20% has been observed for 160 ppm of methane. A prototype device has been fabricated with this sensor and tested for its performance. It could be used to detect methane on site.

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