(Ba,Eu)TiO_3细晶粒陶瓷制备中的影响因素

采用冷压陶瓷技术,分别在1 400℃和1 300℃制备了具有四方结构的(Ba_(1-x)Eu_x)TiO_3和(Ba_(1-x)Eu_x)Ti_(1-x/8)O_3陶瓷.应用X射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)研究Eu含量、Ti空位缺陷和陶瓷化烧结温度的变化对制备(Ba,Eu)TiO_3细晶粒陶瓷的影响因素.结果表明:当x=0.05时,1 300℃制备的(Ba_(1-x)Eu_x)Ti_(1-x/8)O_3陶瓷细化到平均晶粒尺寸小于1μm,1 400℃制备的(Ba_(1-x)Eu_x)TiO_3陶瓷却畸变生长到5μm.而x=0.03时,(Ba_(1-x)Eu_x)TiO_3陶瓷仍能细化到1μm.说明较高的陶瓷化烧结温度并不是晶粒生长的主要原因,Ti空位的存在起到抑制晶粒生长的作用.x≥0.07时,(Ba_(1-x)Eu_x)TiO_3陶瓷为大于5μm的粗晶粒陶瓷,说明Eu含量的继续增加不能抑制晶粒生长.

Influence factors of preparing(Ba,Eu)TiO_3 fine grain ceramics

(Ba_(1-x)Eu_x)TiO_3 and(Ba_(1-x)Eiu_x)Ti_(1-x/8)O_3 ceramics with tetragonal structure were prepared by a cold -pressing ceramic technique under the temperatures of 1 400℃and 1 300℃.respectively.The influence of Eu content,Ti-vacancy defects and sintering temperature on preparing(Ba,Eu)TiO_3 fine grain ceramics were studied using X- ray diffraction(XRD)、scanning electron microscopy(SEM) and atomic force microscope (AFM).The results indicate that the average grain size of(Ba_(1-x)Eu_x)Ti_(1-x/8)O_3(x = 0.05) ceramics prepared under 1 300℃were less than 1μm,but the average grain size of(Ba_(1-x)Eu_x)TiO_3 ceramics prepared under 1 400℃grows to 5μm.Whereas,at x = 0.03,the(Ba_(1-x)Eu_x )TiO_3 ceramics still can refine to 1μm.This means that the higher sintering temperature is not the main reason for grain growth,the existence of Ti-vacancy plays a role in suppressing grain growth.As x≥0.07,the average grain size of(Ba_(1-x)Eu_x)TiO_3 ceramics were still greater than 5μm,illustrating that the continuous increase of Eu content can not inhibit grain growth.