Co_(0.8)Mn_(0.8)Ni_(0.9)Fe_(0.5)O_4纳米粉体的制备及热敏特性研究  

Preparation and Thermal Sensitive Characteristics of the Co_(0.8)Mn_(0.8)Ni_(0.9)Fe_(0.5)O_4 Nanometer Powders

作　　者：张东炎[1,2] 张惠敏[1,2] 靳先静[1,2] 常爱民[1] 

机构地区：[1]中国科学院新疆理化技术研究所,乌鲁木齐830011 [2]中国科学院研究生院,北京100049

出　　处：《无机材料学报》2009年第5期1008-1012,共5页Journal of Inorganic Materials

基　　金：乌鲁木齐市科技攻关项目(G06211002);乌鲁木齐市种子基金(K08141001)

摘　　要：采用共沉淀法,以NH4HCO3为沉淀剂制备了Co0.8Mn0.8Ni0.9Fe0.5O4负温度系数(NTC)热敏电阻纳米粉体材料,研究了不同预烧温度对材料相结构的影响,探讨了不同烧结工艺对NTC热敏电阻材料微观结构和热敏性能的影响.采用X射线衍射(XRD)、综合热分析(TG/DTA)、红外(FT-IR)、扫描电子显微技术(SEM)和激光粒度分析仪对制备的样品进行了表征.结果表明,750℃预烧后的粉体为纯尖晶石相,晶粒粒度为32.1nm,颗粒粒径在50～100nm范围内.通过对不同烧结程序的对比研究发现,当烧结程序为:840℃、1200℃各保温2h,升降温速率为1℃/min时,样品电学性能较好:ρ25℃=1183Ω.cm,B25/50=3034K.分析表明,该烧结程序能有效改善热敏电阻材料的微观结构和热敏性能.根据lnρ-1/T曲线斜率计算了经不同工艺烧结后热敏电阻材料的激活能在0.26eV左右.Nano-powders of Co0.8Mn0.8Ni0.9Fe0.5O4 NTC （Negative Temperature Coefficient） thermistor materials were prepared by co-precipitation method with NH4HCO3 as precipitator. The effects of calcination temperature on the material phase were studied. The influences of different sintering processes on the microstructure and thermal sensitive characteristics of NTC thermistor materials were investigated. The samples were characterized by XRD, TG/DTA, FT-IR, SEM, and Laser Particle Size Analyzer. The results show that the powders calcined at 750℃ are single spinel, the grain size of the powders is about 32.1nm, and the particle size is about 50-100nm. The samples possess better electrical properties： ρ25℃=1183Ω·cm, B25/50=3034K under the process conditions of constant temperature 840℃ and 1200℃ for 2h respectively, the heating and cooling rate of 1℃/min. It is found that proper sintering process can effectively improve the microstructure and thermal sensitive properties of the NTC thermistor materials. According to the calculation from the slope of lnρ-1/T curves, the activation energy is about 0.26eV.

关 键 词：NTC热敏电阻 纳米粉体 共沉淀法 电阻率 

分 类 号：TB33[一般工业技术—材料科学与工程]