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      https://www.ias.ac.in/article/fulltext/boms/032/03/0313-0319

    • Keywords

       

      Pb2Ru2O6.5 formation; RuO2 electrode; Pb(Zr𝑥Ti1–𝑥)O3 (PZT) solid solution; thermodynamic analysis; interface reactions; stability fields.

    • Abstract

       

      Because of its high electrical conductivity and good diffusion barrier properties ruthenium dioxide (RuO2) is a good electrode material for use with ferroelectric lead zirconate–titanate (PZT) solid solutions. Under certain conditions, RuO2 can react with PZT to form lead ruthenate (Pb2Ru2O6.5) during processing at elevated temperatures resulting in lead depletion from PZT. The standard Gibbs energies of formation of RuO2 and Pb2Ru2O6.5 and activities of components of the PZT solid solution have been determined recently. Using this data along with older thermodynamic information on PbZrO3 and PbTiO3, the stability domain of Pb2Ru2O6.5 is computed as a function of PZT composition, temperature and oxygen partial pressure in the gas phase. The results show PbZrO3-rich compositions are more prone to react with RuO2 at all temperatures. Increasing temperature and decreasing oxygen partial pressure suppress the reaction. Graphically displayed are the reaction zones as a function of oxygen partial pressure and PZT composition at temperatures 973, 1173 and 1373 K.

    • Author Affiliations

       

      K T Jacob1 G Rajitha1 V S Saji1

      1. Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012, India
    • Dates

       
  • Bulletin of Materials Science | News

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