文摘
La4Cu3MoO12 is a new (ABO3)n=4 cuprate with mixed B-cations in a ratio of 1:3. When synthesizedat ambient pressure, the structure is not perovskite as expected but rather a homeotype of YAlO3, a rare-earthhexagonal phase. While the P63/mmc and Pmnm space groups can be used to model average structures whichappear in quenched samples; powder, electron, and neutron diffraction data all confirm that a slow-cooledsample crystallizes in the monoclinic space group, P1121/m. The copper and molybdenum are coordinated byoxygen in corner-sharing trigonal bipyramids that are sandwiched between layers of lanthanum cations. In theB-cation layer, the copper cations order into a kagomé-like lattice of triangular clusters. The magnetism hasbeen measured from 2 to 800 K and is highly influenced by the geometric arrangement of the CuII cations. Anantiferromagnetic transition occurs at 5 K, but the sample does not reach a purely paramagnetic state until 460K.