Investigation of the structural, thermo–electrical, and morphological properties of the Bi2O3 ceramics co–doped with rare earths

Payveren M. A., BALCI M., SAATÇİ B., ARI M.

Applied Physics A: Materials Science and Processing, cilt.130, sa.10, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 130 Sayı: 10
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1007/s00339-024-07837-5
  • Dergi Adı: Applied Physics A: Materials Science and Processing
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex
  • Anahtar Kelimeler: Differential thermal analysis, Grain size, Order–disorder transition, Phase stability, Phase transition
  • Erciyes Üniversitesi Adresli: Evet

Özet

In the present study, Bi2O3 compositions co–doped with different rare earth oxides were synthesized for IT–SOFC units utilizing the solid–state reaction process under atmospheric conditions. The cubic δ-phase, an excellent ion conductor, was effectively stabilized in certain samples, with XRD patterns including only peaks of that phase. Compositions with more than 35% total dopant concentration exhibited multiple phase structures, particularly monoclinic α and R-phases. The diffraction peak for the (111) plane moved to greater diffraction angles as doping concentration increased, indicating the influence of multiple dopants on the structural features. The lack of both endothermic and exothermic peaks in the patterns proved that there is no phase transition. Arrhenius plots revealed that when overall dopant concentration increased, electrical conductivity dropped primarily because of a lack of cation polarizability. The highest conductivity measured at 750 °C was found to be 0.0228 S.cm–1, with a corresponding activation energy of 0.86 eV. The FE-SEM pictures confirmed that grain size was not uniform over the surface, and it shrank substantially as the total dopant concentration progressively increased, indicating enhanced microstrain in the lattice due to excessive doping.