Conference Papers

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Author: search.filters.author.Narayanan, M.K.

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    Optical absorption and TEM studies of silver nanoparticle embedded BaO-CaF2-P2O5 glasses
    (American Institute of Physics Inc. subs@aip.org, 2016) Narayanan, M.K.; Shashikala, H.D.
    Silver nanoparticle embedded 30BaO-20CaF2-50P2O5-4Ag2O-4SnO glasses were prepared by melt-quenching and subsequent heat treatment process. Silver-doped glasses were heat treated at temperatures 500 °C, 525°C and 550 °C for a fixed duration of 10 hours to incorporate metal nanoparticles into the glass matrix. Appearance and shift in peak positions of the surface plasmon resonance (SPR) bands in the optical absorption spectra of heat treated glass samples indicated that both formation and growth of nanoparticle depended on heat treatment temperature. Glass sample heat treated at 525 °C showed a SPR peak around 3 eV, which indicated that spherical nanoparticles smaller than 20 nm were formed inside the glass matrix. Whereas sample heat treated at 550 °C showed a size dependent red shift in SPR peak due to the presence of silver nanoparticles of size larger than 20 nm. Size of the nanoparticles calculated using full-width at half-maximum (FWHM) of absorption band showed a good agreement with the particle size obtained from transmission electron microscopy (TEM) analysis. © 2016 Author(s).
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    Optical properties of (50-X)BaO-X(YF2)-50P2O5 glasses
    (American Institute of Physics Inc. subs@aip.org, 2018) Narayanan, M.K.; Shashikala, H.D.
    Glasses with composition (50-X)BaO-X(YF2)-50P2O5 (Y - Ca, Ba, X = 0, 10, 20 mol%) were prepared using conventional melt-quenching technique. Optical parameters of prepared samples such as optical band gap energy increased, while Urbach energy and refractive index decreased with partial substitution of BaO with CaF2 or BaF2 in the glass batch. © 2018 Author(s).
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    Mechanical Instabilities in 2D-SiC with Defects
    (American Institute of Physics Inc., 2023) Madhusoodanan, M.; Narayanan, M.K.; Madam, A.K.
    Elasticity of material is important in understanding the elastic deformation, to flexure, to strain softening. Elastic properties provide the measure of resistance of a system to elastic deformation thus validating its structural stability. Understanding the elasticity of a material is important in understanding their response to any external perturbations. This is required for their synthesis and practical applications. Mechanical stability is determined through the knowledge of second order elastic constants (SOEC) and the higher order elastic constants are necessary to understand the non-linear, anharmonic behaviors. A material is said to be mechanically stable satisfying the Born stability criteria. Here, 2D-SiC, a silicene derivative is introduced with point and topological defects to understand its variation in mechanical properties. Defects namely, mono-, bi- and Stone-Wales types are incorporated into SiC. Computed values of elastic constants implied mechanical instability for C removed monovacancy. All other configurations implied mechanical stability satisfying Born criteria. © 2023 American Institute of Physics Inc.. All rights reserved.