The PTCR(positive temperature coefficient of resistance) nanosized ceramic pow der was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an a...The PTCR(positive temperature coefficient of resistance) nanosized ceramic pow der was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an average crystallite si ze of 35nm with sphere-shaped, whose specific surface area is 27.80m2·g-1 and the crystal structure is abnormal cubical perovskite phase at room temperature. In addition, the nanopowder was pressed into pellets and then sintered accordin g to improved technique which was built based on the data of thermal analysis of the PTCR green-compact to yield PTCR ceramic materials with peculiar microstru cture and higher properties, which has a resistivity at room temperature of ～20 Ω·cm, a temperature coefficient of resistivity of ～19%·℃-1, a withstand v oltage intensity of >160V·mm-1 and a resistivity jump of >105.展开更多
文摘The PTCR(positive temperature coefficient of resistance) nanosized ceramic pow der was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an average crystallite si ze of 35nm with sphere-shaped, whose specific surface area is 27.80m2·g-1 and the crystal structure is abnormal cubical perovskite phase at room temperature. In addition, the nanopowder was pressed into pellets and then sintered accordin g to improved technique which was built based on the data of thermal analysis of the PTCR green-compact to yield PTCR ceramic materials with peculiar microstru cture and higher properties, which has a resistivity at room temperature of ～20 Ω·cm, a temperature coefficient of resistivity of ～19%·℃-1, a withstand v oltage intensity of >160V·mm-1 and a resistivity jump of >105.
基金Natural Science Foundation of China(51202291,51302314)Aid Program for Innovative Group of National University of Defense TechnologyAid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
