Inhibition of secondary phase formation with minor copper doping on sol–gel derived PbTiO3 powders

Erünal E.

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, cilt.101, ss.484-492, 2022 (SCI-Expanded)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 101
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1007/s10971-021-05700-0
  • Dergi Adı: JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, PASCAL, Aerospace Database, Applied Science & Technology Source, Biotechnology Research Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, Metadex, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.484-492
  • Çukurova Üniversitesi Adresli: Evet

Özet

Sol–gel is a practical method but it might be hard to control secondary phase formations during ceramic powder synthesis. In order to inhibit secondary phase formation, amount of copper doping was investigated for sol–gel derived PbTiO3 samples. A comparative study was conducted with undoped and (5, 10, 20, 40, and 50%) copper doped Pb(Ti(1−x)Cux)O3 powders to investigate possible secondary phase formations and understand defect chemistries of the materials. It was found that upon addition of minor (5%) copper, the formation of monoclinic and pyrochlore lead oxide phases can be suppressed without changing other process parameters including calcination temperature at 650 °C. However, above 5% doping, the Rietveld analysis through XRD spectra showed that the ratio of PbTiO3 phase decreased for samples doping amount higher than 5% as a result of CuO formation. The shift of Curie temperature from 490 to 480 °C were observed for all materials via thermal analysis. This was attributed to formation of cation vacancies within the perovskite structure. Moreover, for 5% copper doped material Cu2+ ion was found in the octahedral position of perovskite structure via EPR spectroscopy. The spin Hamiltonian parameters were estimated as gzz = g|| = 2.34 > gxx = gyy = g⊥ = 2.07 and A||= 341 MHz. The derived parameters were used to determine oxygen vacancies associated with Cu2+ center with a semiempirical model. The type of the oxygen defect enabled the prediction of Ti–O bond that was found only for copper doped samples with FT-IR measurement