TY - JOUR
T1 - Structural and electrical properties of MgO-doped Mn1.4Ni1.2Co0.4-xMgxO4 (0 ≤ x ≤ 0.25) NTC thermistors
AU - Park, K.
AU - Kim, S. J.
AU - Kim, J. G.
AU - Nahm, S.
N1 - Funding Information:
This work was supported by Small and Medium Business Administration in Korea.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
N2 - 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.
AB - 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.
KW - Electrical conductivity
KW - Electrical properties
KW - NTC thermistor
KW - Sintering
KW - Transition metal oxides
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U2 - 10.1016/j.jeurceramsoc.2006.07.002
DO - 10.1016/j.jeurceramsoc.2006.07.002
M3 - Article
AN - SCOPUS:33751507893
SN - 0955-2219
VL - 27
SP - 2009
EP - 2016
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 4
ER -