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      https://www.ias.ac.in/article/fulltext/boms/023/06/0491-0494

    • Keywords

       

      Coefficient of thermal expansion; low thermal expansion; NZP; ceramic; dilatometer; anisotropy

    • Abstract

       

      Ba1.5-xSrxZr4P5SiO24 compounds withx = 0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5, belonging to the low thermal expansion NZP family were synthesized by the solid state reaction method. The XRD pattern could be completely indexed with respect to$$R\bar 3$$ space group indicating the ordering of vacancy at the divalent cation octahedral sites. The microstructure and bulk thermal expansion coefficient from room temperature to 800°C of the sintered samples have been studied. All the samples show very low coefficient of thermal expansion (CTE), withx = 0 samples showing negative expansion. A small substitution of strontium in the pure barium compound changes the sign of CTE. Similarly,x = 1.5 sample (pure strontium) shows a positive CTE and a small substitution of barium changes its sign.X = 1.0 and 1.25 samples have almost constant CTE over the entire temperature range. The low thermal expansion of these samples can be attributed to the ordering of the ions in the crystal structure of these materials

    • Author Affiliations

       

      P Srikari Tantri1 K Geetha1 2 A M Umarji1 2 Sheela K Ramasesha1

      1. Materials Science Division, National Aerospace Laboratories, Bangalore - 560 017, India
      2. Materials Research Centre, Indian Institute of Science, Bangalore - 560 012, India
    • Dates

       
  • Bulletin of Materials Science | News

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      Posted on July 25, 2019

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