Structural study of the new complex oxides Ba5−ySryR2−xAl2Zr1+xO13+x/2 (R = Gd−Lu, Y, Sc)
Structural study of the new complex oxides Ba5−ySryR2−xAl2Zr1+xO13+x/2 (R = Gd−Lu, Y, Sc)
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新型复合氧化物Ba5−ySryR2−xAl2Zr1+xO13+x/2 (R = Gd−Lu, Y, Sc)的结构研究
DOI：
10.1006/jssc.1995.1329
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发表时间：
1995
影响因子：
5.4
通讯作者：
S. Amelinckx
中科院分区：
文献类型：
--
作者：
R. Shpanchenko;A. Abakumov;E. Antipov;L. Nistor;G. Tendeloo;S. Amelinckx
合成了六方钙钛矿型复合氧化物Ba 5 R2 Al 2 ZrO 13（R = Gd-Lu，Y）和Ba 5-ySrySc1.33Al2Zr1.66O13.33，并用X射线粉末衍射、电子衍射和高分辨电子显微镜进行了研究。所有的化合物具有相似的晶体结构的基础上的10 H密堆积（cchcc）2堆积的BaO 3- x层。阴离子空位位于h -型层中，根据R3+阳离子的类型，可以以有序或无序的方式出现.结果表明，稀土元素的半径严重影响的组成和这些化合物的晶体结构中的顺序的可能性。高分辨率电子显微镜显示存在大量的堆叠缺陷，它们的数量和大小，这取决于稀土元素的类型。这些化合物的晶体结构可以形式上描述为沿c轴沿着交替排列的BaZrO 3和β-Ba 2ScAlO 5型块体的共生结构。
Abstract New anion-deficient hexagonal perovskite-like complex oxides Ba 5 R 2 Al 2 ZrO 13 ( R = Gd-Lu, Y) and Ba 5- y Sr y Sc 1.33 Al 2 Zr 1.66 O 13.33 were synthesized and studied by X-ray powder diffraction, electron diffraction, and high-resolution electron microscopy. All the compounds have similar crystal structures based on the 10H close-packed ( cchcc ) 2 stacking of BaO 3- x layers. The anion vacancies are located in the h -type lamellae and may occur either in an ordered or in a disordered manner, depending on the R 3+ cation type. It is shown that the radius of the rare-earth element critically influences the composition and the possibility of ordering in the crystal structures of these compounds. High resolution electron microscopy revealed the presence of a large number of stacking defects, their number, and size, depending on the type of the rare-earth element. The crystal structures of these compounds can be formally described as intergrowth structures with an alternation of BaZrO 3 and β-Ba 2 ScAlO 5 -type blocks along the c axis.