烧结温度对BaLaxBi1-xO3体系材料微观形貌及NTC特性的影响

Effect of Sintering Temperature on Micro-morphology and NTC Characteristics of BaLaxBi1-xO3 System Materials

选用固相烧结法制备BaLaxBi1-xO3体系材料,样品的微观形貌及物相由XRD和SEM分析得出。通过分析发现实验样品经预烧后形成单一固溶体,样品晶界清晰,晶粒粗细均匀,且晶界致密度随烧结温度增加而增大。实验结果表明:样品在特定的温度区间内呈现出典型的NTC效应;适宜的预烧温度区间为800~900℃,最佳烧结温度区间为1050~1100℃;材料常数B值由900℃的3629 K减小到1050℃的3300 K,电阻率ρ由1103Ω·cm减小到166Ω·cm。

The solid-state sintering method was picked to prepare the BaLaxBi1-xO3 family materials.The microscopic configurations and phases of the samples were analyzed in depth by XRD and SEM technologies.By reviewing the analysis,it is found that the samples in the experiments form a single solid solution after calcination,and the grain cell boundaries appear to be more distinguishable and the coarseness of the grain tend to be more event.Also,the grain boundaries become more compacted when the temperature of the sintering hikes up.The experimental results show that the sample exhibits NTC characteristics in a specific temperature range;the suitable calcination temperature range is 800~900℃,and the optimal sintering temperature range is 1050~1100℃;the value of material constant B is reduced from 3629 K at 990℃ to 3300 K at 1050℃,and the resistivityρis reduced from 1103Ω·cm to 166Ω·cm.