Quasi-one-dimensional oxides;
Synthesis;
Crystal structures;
Magnetic properties;
CRYSTAL-STRUCTURE;
PHASES;
GROWTH;
D O I:
10.1016/j.jallcom.2011.03.040
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
The complex oxide Sr4LiMn2O9 belonging to the A(3n+3m)A'nMn3m+nO9m+6n family (m = 3, n = 1) was prepared from a mixture of SrCO3 and LiMn2O4 in a microwave furnace by the solid state reaction. The results of structural refinements and magnetic properties are presented. The crystal structure of Sr4LiMn2O9 was solved using simultaneously X-ray and neutron diffraction data with the GSAS program in the space group P321 with unit cell parameters: a = 9.5721(7) angstrom, c = 7.8264(5) angstrom, V = 621.025 angstrom(3), Z = 3. Sr4LiMn2O9 was found to contain 2 independent 1D chains of face-shared polyhedrons with a sequence of two octahedrons and one trigonal prism. The chains are separated by strontium cations. The refinement results show that the octahedrons and trigonal prisms in the first chain orderly contain Mn and Li, respectively, whereas the second chain is characterized by mixed occupation of these structural positions. The temperature dependence of the magnetic susceptibility of Sr4LiMn2O9 was found to be due to antiferromagnetically coupled dimers from magnetic Mn cations. (C) 2011 Elsevier B.V. All rights reserved.