高压烧结法合成致密纳米BaTiO_3陶瓷结构和铁电性能研究  

Structure and Ferroelectric Properties of Dense Nanocrystalline BaTiO_3 Ceramics Prepared by High Pressure Sintering Method

作　　者：李鹏飞[1] 靳常青[2] 肖长江[2] 潘礼庆[1] 王晓慧[3] 

机构地区：[1]北京科技大学物理系,北京100083 [2]中国科学院物理研究所,北京100080 [3]清华大学材料科学与工程系,北京100084

出　　处：《高压物理学报》2007年第3期249-252,共4页Chinese Journal of High Pressure Physics

基　　金：973课题资助项目(2002CB613301)

摘　　要：在6 GPa压力、1 000℃温度条件下制备了致密的纳米BaTiO3陶瓷,合成样品的平均晶粒尺寸为50 nm,理论密度在97%以上。通过介电测量,观察到了样品宽化的相变峰,它与粗晶陶瓷的相变峰大不相同。由于90°电畴的减少和退极化场的存在,观察到了细长的电滞回线,它是样品铁电性存在的有力证据,表明钛酸钡陶瓷的临界尺寸在50 nm以下。　Dense nanocrystalline BaTiO3 ceramics with a grain size of 50 nm were prepared under 6 GPa at 1 000 ℃ using a high pressure sintering method.The sintered bulk is uniform and the relative density is above 97%.We annealed the ceramic samples in oxygen to eliminate the oxygen vacancies caused by high pressure.After anneal,several broadened peaks were observed through dielectric measurements.However,these peaks are very different from those of coarser-grained ceramics.The observation of polarization hysteresis loop provides the solid evidence of ferroelectricity in these nano-sized BaTiO3 ceramics.It is believed that the absence of 90° domains and the existence of depolarization field caused by nonferroelectric grain boundaries contribute to the slim loop.

关 键 词：高压烧结 铁电 纳米晶BaTiO3陶瓷 电畴 

分 类 号：O521.2[理学—高压高温物理]