Frampton Philip P C, Battle Peter D, Ritter Clemens
Inorganic Chemistry Laboratory, Oxford University, UK.
Inorg Chem. 2005 Oct 3;44(20):7138-42. doi: 10.1021/ic050949s.
Polycrystalline samples of Ln18Li8Rh5O39 (Ln = La, Pr) have been synthesized by the ceramic method and characterized by X-ray and neutron diffraction. The compounds crystallize in the cubic space group Pmn, with a0 approximately 12.1 Angstroms. The unit cell contains four intersecting 111 chains, each comprised of an alternating sequence of face-sharing RhO6 octahedra and LiO6 trigonal prisms. The octahedra located at the points of intersection contain Rh4+, whereas the remainder contain Rh3+; the compounds thus contain a charge-ordered arrangement of the two cations. The polyhedral chains are enclosed in tunnels formed by the Ln-O sublattice. The magnetic properties of the two new compounds are discussed briefly: both are paramagnetic over the temperature range 5 < TK < 300.
采用陶瓷法合成了Ln18Li8Rh5O39（Ln = La，Pr）的多晶样品，并通过X射线和中子衍射进行了表征。这些化合物结晶于立方空间群Pmn中，a0约为12.1埃。晶胞包含四条相交的111链，每条链由面共享的RhO6八面体和LiO6三角棱柱交替序列组成。位于交点处的八面体包含Rh4+，其余的包含Rh3+；因此，这些化合物包含两种阳离子的电荷有序排列。多面体链被包裹在由Ln - O亚晶格形成的隧道中。简要讨论了这两种新化合物的磁性：在5 < TK < 300的温度范围内，它们均为顺磁性。
