摘要
用溶胶-凝胶(Sol-gel)技术及柠檬酸自燃方法制备了CrxNi1.0Mn2.0-xO4(x=0,0.1,0.2,0.3,0.4)系列新型的纳米氧化物超细粉体。并将得到的超细粉体经过压片、烧结、封装等工艺制得一类精度与稳定性均优异的负温度系数热敏电阻。用扫描电镜(SEM)、X射线粉末衍射(XRD)观测与确定了超细粉体与烧结体的晶粒大小、形貌特征与晶相。同时研究了晶粒的微结构随烧结温度的变化规律。用电阻测量手段表征了烧结体材料的电阻及材料的老化性能。研究结果表明:随着铬离子含量的增加,所得热敏电阻的阻值增大。在所有获得的材料中,其灵敏度B值均大于4100 K。经过老化处理后,其老化稳定性提高46%。可认为该系列热敏电阻是一种具有实际应用价值的负系数热敏电阻。
The novel nano-ultrafine powders of CrxNi1.0Mn2.0-xO4 （x=0, 0.1, 0.2, 0.3, 0.4） materials were prepared via sol-gel method and citrate auto-ignition route. After the precursor powders were pressed, sintered and covered, the negative temperature coefficient （NTC） thermistor with high precision and aging stability was prepared. The size of micro-crystal, morphology and the phase of micro-crystal were observed and confirmed using scanning electron microscopy （SEM）, and X-ray diffraction （XRD）. The variety of micro-structure of the sintered samples with sintering temperature was also investigated. The electrical properties and aging stability were measured by resistance measurements. It shows that the Cr substitution for Mn increased the electrical resistivity. The ceramics had a sensitivity index B which is higher than 4100 K and the aging stability can be increased by 46%. This series of NTC thermistor could be considered as practical materials for NTC thermistor applications.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2008年第A02期513-517,共5页
Rare Metal Materials and Engineering
基金
浙江省科技厅(2007C21G2070001)
宁波市科学技术局(20058100026)
