Effect of ZrO<sub>2</sub> Addition on the Microstructure and Electrical Properties of Ni-Mn Oxide NTC Thermistors

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doi:2003.40.1.11

J. Korean Ceram. Soc. > Volume 40(1); 2003 > Article

Journal of the Korean Ceramic Society 2003;40(1): 11.
doi: https://doi.org/10.4191/kcers.2003.40.1.011

Ni-Mn 산화물 NTC 서미스터의 미세구조와 전기적 특성에 미치는 ZrO₂첨가의 효과

박경순, 방대영¹, 윤성진¹, 최병현²

세종대학교 신소재공학과?신소재연구소
¹세종대학교 신소재공학과·신소재연구소
²요업기술원 신기능재료연구부

Effect of ZrO₂ Addition on the Microstructure and Electrical Properties of Ni-Mn Oxide NTC Thermistors

ABSTRACT

The effect of$ZrO_2$addition on the microstructure and electrical properties of Ni-Mn oxide NTC thermistors was studied. Major phases present in the sintered bodies of $Ni_{1.0}Mn_{2-x}Zr_xO_4$ were the solid solutions of Ni-Mn-Zr oxides with a cubic spinel structure and the $ZrO_2$ with a tetragonal structure. The $ZrO_2$ was formed by the partial decomposition or incomplete formation of the Ni-Mn-Zr oxides during sintering. With increasing the amount of added $ZrO_2$, the $ZrO_2$ phase increased. The relationship between log resistivity (log p) and the reciprocal of absolute temperature (1/T) of the NTC thermistors prepared was linear, indicative of NTC characteristics. The resistivity, B constant and activation energy of the thermistors increased with increasing $ZrO_2$ content.磩

Key words: Ni-Mn-Zr Oxide, NTC thermistors, Electrical resistivity, B Constant, Sintering, Microstructure