Disappearance and recovery of colossal permittivity in (Nb+Mn) co-doped TiO2

Chao Yang, Xianhua Wei, Jianhua Hao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

18 Citations (Scopus)

Abstract

We investigate the effects of doping and annealing on the dielectric properties of metal ions doped TiO2ceramics. Colossal permittivity (CP) above 104was observed in single Nb ion doped TiO2, which was dominated by electron transport related interfacial polarization. Moreover, the CP can be dropped to 120 when simultaneously introducing Mn ion into the sample. The disappearance of CP behaviors maybe due to the multivalence of Mn which would inhibit the reduction of Ti4+to Ti3+, and thus reduce delocalized electrons. Interestingly, the CP was recovered for the (Nb+Mn) co-doped TiO2after post-sintering heat treatment in N2atmosphere. The recovery of CP in the sample after annealing can be ascribed to the semiconducting grain and the insulating grain boundary, according to impedance spectroscopy. We therefore believe that this work can help us understand the mechanism of CP from a new perspective.
Original languageEnglish
Pages (from-to)12395-12400
Number of pages6
JournalCeramics International
Volume44
Issue number11
DOIs
Publication statusPublished - 1 Aug 2018

Keywords

  • Annealing
  • Colossal permittivity
  • Impedance spectroscopy
  • Mn-doped TiO 2
  • XPS

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Materials Chemistry

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