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研究了CeO_2对MgO-CaO材料烧结及导电性影响,发现少量CeO_2的引入可明显提升材料的烧结致密化程度,这归因于CeO_2与CaO的发生有限固溶反应,增大了Ca~(2+)空位的浓度,有利于Ca~(2+)的扩散。烧结过程中随着晶界的迁移,方镁石与方钙石晶粒逐渐长大,晶粒间的气孔逐渐排除,但方镁石晶粒内部出现气孔。MgO-CaO材料的导电性增强的实质在于CaO微观结构的改变,即Ca~(2+)空位的形成及导电载流子浓度的增大。
The effect of CeO_2 on the sintering and electrical conductivity of MgO-CaO materials was investigated. It was found that the introduction of a small amount of CeO_2 can significantly improve the sintering densification of the material, which is attributed to the limited solid solution reaction of CeO_2 and CaO, +) Vacancy concentration is conducive to the diffusion of Ca ~ (2+). Sintering process with the migration of grain boundaries, periclase and calcite grains gradually grow, gradually remove the pores between the grains, but perforation within the periclase grains. The enhancement of conductivity of MgO-CaO material lies in the change of CaO microstructure, namely the formation of Ca2 + vacancies and the increase of conductive carrier concentration.