La0．5Ca0．5MnO3钙钛矿微晶的 NH＋4辅助水热合成及晶面调控

摘要

In order to study the relationship of material’s physical properties and materials special facet ,the special facets need to be obtained firstly .La0.5Ca0.5MnO3 microcrystals with different morphologies were obtained by hydrothermal method using dif‐ferent concentration of urea ,KOH and adjusting the reaction temperature .Characterization methods of powder X‐ray diffraction (XRD) ,scanning electron microscope (SEM ) were used to show the crystal structure and morphology information for as‐pre‐pared products .The synthesis condition and reactant concentration play important roles in crystal facet tailoring process .The op‐timal route to prepare octahedral shape of La0.5Ca05MnO3 microcrystal wasdiscussed and its corresponding facet tailoring mecha‐nism was also set up ,which is important for further study and application on the relationship of structure and properties of per‐ovskite structure oxides .%为了研究特殊晶面与晶体材料的物理性质的关系，需要合成具有特殊晶面的晶体。采用水热法，通过调节反应过程中温度、尿素和KOH的质量，合成了具有不同形状和晶面的La0．5 Ca0．5 MnO3钙钛矿微晶。利用X射线衍射仪、扫描电子显微镜对晶体的形貌、结构进行了表征，比较了不同温度、不同尿素和KO H质量对产物结构和形状等的影响，并对反应机理进行了研究。提出了制备八面体形状La0．5Ca0．5MnO3微晶的最优方案，即温度为260℃、尿素质量为2．25 g ，且KOH质量为9 g。为研究特殊晶面与材料的物化性质和材料的构效关系提供了依据。