Crystal layered perovskite-like

Aleksandrov K.S. and Barotolome J., Octahedral Tilt Phases in Perovskite-like Crystals with Slabs Containing an Even Number of Octahedral Layers, J. Phys. Condens. Matter., 6 (1994) pp.8219-8235. 

In contrast to the situation in the 3-dimensional perovskite structure, two distinct sites are available for Ln and Ba cations, in this quasi-2-dimentional crystal structure. A 12-coordinate site (Ba/Lal) is situated within the perovskite-like blocks, and a 9-coordinate (Ba/Ln2) is situated on the edge of the blocks referred to as the rock-like layer. The availability of these two sites introduces an additional parameter, which has an influence over the properties of this phase, namely, the degree of cation ordering on the Ba/Ln sublattice [6]. Therefore, it is worthy that the pure phase containing Mn ion only is... 

Figure 42 Crystal structure of a pillared perovskite material, LasResMnOie. The grey and white octahedra represent the MnReOe site-ordered perovskite like layers and the black octahedra, the Re20io edge-sharing dimers. The white spheres show the La ion positions...

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