Microwave synthesis, structure, and magnetic properties of quasi-one-dimensional complex oxide Sr4LiMn2O9

The complex oxide Sr4LiMn2O9 belonging to the A3n+3mA′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) Å, c = 7.8264(5) Å, V = 621.025 Å3, 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.

► Sr4LiMn2O9 was prepared by microwave synthesis. >Real composition is Sr4Li0.89Mn2.11O9.
► The structure contain 2 independ 1-D chains of dimers octahedra and trigonal prisms.
► Magnetic properties of Sr4LiMn2O9 cause of antiferromagnetically caupled Mn–Mn dimers.