| 학회 | 한국재료학회 |
| 학술대회 | 2010년 봄 (05/13 ~ 05/14, 삼척 팰리스 호텔) |
| 권호 | 16권 1호 |
| 발표분야 | A. Information Processing and Sensing(정보소재 및 센서) |
| 제목 | Effect of process conditions on the electrical properties of Thin film Mn-Ni-Fe NTC Thermistor |
| 초록 | Negative temperature coefficient (NTC) thermistors are thermally sensitive resistors whose resistance decreases with increasing temperature. There is a large choice of NTC materials, and the mostly used materials are Ni- and Mn-based spinel oxides of general formula AB2O4 such as Cu-Ni-Mn-O, Ni-Mn-O and Fe-Ni-Mn-O. In the spinel, oxide ions are cubic close packed and cations are situated at the tetrahedral (A) and octahedral (B) sites. The electrical conduction in the spinel oxides is generally described by a small polaron hopping mechanism. Spinel structured Mn-Ni-Fe exhibits an exponential dependence of resistance on temperature, where the resistance of the material decreases with increasing temperature. This NTCR property makes it suitable to be used as temperature sensor (thermistor). In this study, the Mn-Ni-Fe target with diameter 2 inch was prepared using the solid reaction with the staring materials were Mn2O3, NiO and Fe2O3. The mixed powder was then calcined at 1200℃ in air for 4hrs. The as-obtained powders were blended with an organic binder, then spray for granule powder. Disk-shaped powder compacts of diameter 2inch and thickness 3mm were formed by uniaxial pressing at 80MPa followed by isostatically pressing at 200MPa. The powder compacts were heated in air to 1250℃ at a rate 150℃/h and kept at that temperature for 2hrs. Thin films of Mn-Ni-Fe were deposited on oxide coated ＜100＞ silicon (SiOx), using RF magnetron sputtering in an oxygen/argon atmosphere at 400℃ and 80W. The deposed thin film Mn-Ni-Fe was heat treatment from 300℃ to 600℃ for 1hr, respectively. Also the deposed thin film Mn-Ni-Fe gave aging in different environments for control of crystal phase. The resistance of the thin films was measured as a function of temperature for both as-deposited and aging. The resistance versus temperatures as measurements were done form room temperature up to 150℃. The resistivity and B constant of Mn-Ni-Fe thermistors were show about from 40㏀•㎝ to 1315㏀•㎝and from 4910 to 5100 according to aging conditions, respectively. The this time, thin film thickness of the Mn-Ni-Fe thermistors was from 6500 to 9500Å. The evaluation test confirmed that thin film Mn-Ni-Fe thermistors performed well showing very high thermal sensitivity. |
| 저자 | Mi-Jai Lee1, 박정묵2, 김세기1, 김진호2 |
| 소속 | 1KICET, 2전자광소재센터 |
| 키워드 | NTC thermistor; Thin film; Mn-N-Fe system |
