Preparation and electrical properties of FexCu0.10Ni0.66Mn2.24¿xO4 (0 <x <0.90) NTC ceramics

Dao-lai Fang, Chusheng Chen, Aloysius J.A. Winnubst

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31 Citations (Scopus)

Abstract

In this paper, the dense FexCu0.10Ni0.66Mn2.24−xO4 (0 ≤ x ≤ 0.90) ceramics with accurate stoichiometry are prepared by the route of solid-state coordination reaction. The effect of Fe addition on the electrical properties of the ceramics has been investigated by powder X-ray diffraction (XRD), electrical measurement and thermogravimetric analysis. With Fe content x increasing from 0 to 0.45, the resistivity remains almost unchanged, whereas the thermal constant B decreases drastically. With a further increase in x from 0.45 to 0.90, both the resistivity and the thermal constant B increase. With a rise in x from 0 to 0.9, the aging coefficient drops from 19.9 to 0.6%. The remarkable improvement of the electrical stability can be attributed to the mechanism that substitution of Fe3+ for Mn2+ and Mn3+ restrains the formation of cation vacancies in spinel lattice, thus the modification of cation distribution and the consequent aging under thermal stress is greatly alleviated.
Original languageUndefined
Pages (from-to)286-291
JournalJournal of alloys and compounds
Volume454
Issue number1-2
DOIs
Publication statusPublished - 2008

Keywords

  • METIS-250429
  • IR-71883

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