为提高合成CaTiO3材料的烧结性能,以分析纯的CaO和TiO2为原料,以Er2O3为添加剂,按照CaO、TiO2反应的化学计量比配料,在混合粉末中分别外加质量分数1%、2%、3%和4%的Er2O3进行球磨混合,通过固相反应烧结法合成钛酸钙材料.利用X射线衍射仪、扫描电子显微镜、能谱仪分别对试样的物相组成、显微形貌及组成进行了分析表征.用衍射仪配套软件X'Pert High Score Plus计算钛酸钙晶胞参数,分析了离子间取代行为和晶胞体积变化的关系.结果表明:伴随Er2O3的少量添加,Er3+与Ti4+之间优先发生置换反应,致使CaTiO3的晶胞结构发生畸变,晶胞体积增大.当进一步提高Er2O3添加量时,取代反应在Er3+与Ca2+之间发生,CaTiO3晶胞发生收缩,晶胞体积呈减小趋势.Er2O3与CaTiO3的固溶造成的晶格畸变促进了离子间的扩散,加速了固相反应烧结,造成的结构缺陷促进了CaTiO3晶粒的生长.同时,随着煅烧温度的升高,结构中热缺陷数量增多,提高了钛酸钙材料的烧结性能.%CaTiO3materials were prepared using analytically pure CaO and TiO2as starting materials,and Er2O3as an additive to improve the sintering characteristics.After ball milling the stoichiometric CaO and TiO2,and extra-added Er2O3(1%,2%,3%,and 4%,by mass),the mixtures were synthesized into CaTiO3 materials by the solid reaction sintering method.The phase composition,microstructure and element com-position of the products were investigated by XRD,SEM and EDS.The cell parameters were determined by X'Pert High Score Plus software to analyze the relationship between ionic substitution and cell volume.The results indicate that when adding a little Er2O3,the displacement reaction between Er3+and Ti4+happens preferentially,the CaTiO3cell structure distorts,thus the cell volume increases.When the addition of Er2O3 increases,the displacement reaction between Er3+and Ca2+happens,the CaTiO3cell shrinks,thus the cell volume decreases.The lattice distortion caused by the solid solution of Er2O3and CaTiO3accelerates the ion diffusion and promotes the sintering of CaTiO3material,and the occurred structure defects accelerate the growth of CaTiO3grains.With the calcining temperature rising,thermal defects increase,and the sinte-ring property of synthesized CaTiO3is promoted.
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