Structural and electrical properties of MgO-doped Mn1.4Ni1.2Co0.4-xMgxO4 (0 ≤ x ≤ 0.25) NTC thermistors

K. Park, S. J. Kim, J. G. Kim, Sahn Nahm

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

We have prepared polycrystalline Mn1.4Ni1.2Co0.4-xMgxO4 (0 ≤ x ≤ 0.25) samples using a solid-state reaction process and investigated the MgO doping effect on the microstructure and the electrical properties. It was found that, as the amount of Mg content in the Mn1.4Ni1.2Co0.4-xMgxO4 samples increased, both the grain size and density decreased. The as-sintered Mn1.4Ni1.2Co0.4-xMgxO4 samples contained Mn- and Ni-rich phases with cubic spinel structure. The MgO-doped Mn1.4Ni1.2Co0.4-xMgxO4 negative temperature coefficient (NTC) thermistors provided various electrical properties, depending on Mg content. The electrical resistivity, B25/85 constant, and activation energy of the Mn1.4Ni1.2Co0.4-xMgxO4 NTC thermistors increased with increasing Mg content. The values of ρ25, B25/85 constant, and activation energy of the NTC thermistors were 11,185-20,016 Ω cm, 3635-4032 K, and 0.313-0.348 eV, respectively.

Original languageEnglish
Pages (from-to)2009-2016
Number of pages8
JournalJournal of the European Ceramic Society
Volume27
Issue number4
DOIs
Publication statusPublished - 2007 Jan 1

Keywords

  • Electrical conductivity
  • Electrical properties
  • NTC thermistor
  • Sintering
  • Transition metal oxides

ASJC Scopus subject areas

  • Ceramics and Composites

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