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 language | English |
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Pages (from-to) | 2009-2016 |
Number of pages | 8 |
Journal | Journal of the European Ceramic Society |
Volume | 27 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2007 |
Bibliographical note
Funding Information:This work was supported by Small and Medium Business Administration in Korea.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
Keywords
- Electrical conductivity
- Electrical properties
- NTC thermistor
- Sintering
- Transition metal oxides
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry