| 초록 |
In this study, $ Ni_{0.79}(Mn_{2.21-x}Cu_x)O_4$ (x=0~0.25) specimens were prepared by using a conventional mixed oxide method. All specimens were sintered in air at $1,200^{ circ}C$ for 12 h and cooled at a rate of $2^{ circ}C/min$ to $800^{ circ}C$ , subsequently quenching to room temperature. We investigated the structural and electrical properties of $ Ni_{0.79}(Mn_{2.21-x}Cu_x)O_4$ specimens with variation of CuO amount for the application of NTC thermistors. As results of X-ray diffraction patterns, all specimens showed the formation of a complete solid solution with cubic spinel phase. The relationship between ln ${ rho}$ and the reciprocal of absolute temperature(1/T) for the NTC thermistors was shown linearity, which exhibited the typical NTC thermistor properties. With increasing the amount of CuO, resistivity at room temperature, B-value, and temperature coefficient resistance decreased. |
