• Dependence of oxygen desorption kinetics on processing methods of SrCoO$_{2.5}$

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/044/0057

    • Keywords

       

      Oxygen ion diffusion; oxygen non-stoichiometry; mixed ion electron conductor; perovskite oxide; desorption kinetics.

    • Abstract

       

      The effect of processing methods on oxygen storage and exchange kinetics of brownmillerite (BM) SrCoO$_{2.5}$ is compared in terms of their reversible oxygen incorporation and desorption kinetics. BM SrCoO$_{2.5}$ was synthesized through two different methods; solid-state synthesis and the nitrate–citrate gel method, both followed by Al foil pad quenching. Oxygen storage characteristics of synthesized samples were analysed using a home-built volumetric set-up. The maximum oxygenation achievable for BM SrCoO$_{2.5}$ under prevailing conditions of O$_2$ partial pressure (16 bar O$_2$), temperature (673 K) and time (1 h) was unaltered, regardless of the synthesis method. Oxygen exchange kinetics of desorption was faster in the nitrate–citrate synthesized sample than in the solid-state synthesized sample. The kinetics of desorption correlated with the crystallite and particle sizes of the samples. The mechanism of desorption follows nucleation and growth model for nitrate–citrate synthesized sample, while it follows contracting sphere model for solidstate synthesized sample.

    • Author Affiliations

       

      ASWATHY M NARAYANAN1 ARUN M UMARJI

      1. Materials Research Centre, Indian Institute of Science, Bengaluru 560012, India
    • Dates

       
  • 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

© 2021-2022 Indian Academy of Sciences, Bengaluru.