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      https://www.ias.ac.in/article/fulltext/boms/033/03/0319-0324

    • Keywords

       

      Layered double hydroxide; thermal decomposition; topochemical relationship.

    • Abstract

       

      The layered double hydroxide (LDH) of Co with Al decomposes to yield an oxide residue with the spinel structure below 250°C. The decomposition reaction is preceded by the formation of an intermediate hydroxide in which the metal hydroxide layers are regularly stacked about the 𝑐-crystallographic axis, but the layers themselves are aperiodic. Aperiodicity is modeled by locating randomly chosen Co2+ ions in tetrahedral sites in the interlayer region. This phase is characterized by a single strong basal reflection in its powder diffraction pattern. All other reflections are extinguished on account of

      1. turbostratic disorder which destroys all ℎ𝑘𝑙 reflections and

      2. layer aperiodicity, which destroys all two dimensional ℎ𝑘 reflections.

      Given its topochemical relationship with the spinel structure, such an intermediate is a necessary precursor to spinel formation.

    • Author Affiliations

       

      A V Radha1 Grace S Thomas1 P Vishnu Kamath1 Churchil A Antonyraj2 S Kannan2

      1. Department of Chemistry, Central College, Bangalore University, Bangalore 560 001, India
      2. Discipline of Inorganic Materials and Catalysis, Central Salt and Marine Chemicals Research Institute, Bhavnagar 364 002, India
    • Dates

       

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