低温烧结铁氧体粉料的最新进展

以国家“86 3”计划重大项目和第八届国际铁氧体会议重要论文为据 ,综合分析、论述了低温烧结铁氧体粉料的进展状况。重点介绍了固相反应法 Ni Cu Zn铁氧体、Mg Cu Zn铁氧体和六角晶系 Co2 Z铁氧体。同时报道了具有世界领先水平的软化学法 Ni Cu Zn铁氧体和六角晶系 Co2 Z铁氧体成果

Study on the electrical properties of the grain boundary of ZnO varistor

Relations between capacitance and voltage, dielectric and dissipation properties of low breakdown voltage ZnO varistors are studied by using HP41912A low frequency impedance analysis meter. The effects of dopants on electrical properties of ZnO grain-boundary are analyzed. The mechanism of the effect of heat treatment on the electrical properties of ZnO grain-boundary is discussed. It is concluded that the donor concentration remains nearly the same while barrier height, density of states at the interface and depletion width increase when the concentration of doped Na+ increases. When samples annealed in air atmosphere, donor concentration and barrier height drops while donor concentration remains unchanged; and when samples are annealed in argon gas, barrier height drops more than in air. In the range of 105～106 Hz, εr decreases sharply and dissipation factor reaches to its peak. The peak possesses typical broadened Debye relaxation Peak characteristics.(8 refs.)