Synthesis and characterization of O3-Na3LiFeSbO6: A new honeycomb ordered layered oxide

A new compound Na3LiFeSbO6 has been synthesized by conventional solid state methods and investigated using X-ray diffraction, DC magnetic susceptibility, 57Fe Mössbauer spectroscopy and optical measurements. This compound crystallizes in a monoclinic unit cell and is related to a family of honeycomb ordered layered oxide materials where Na+ fills octahedral interlayer sites between Li1/3Fe1/3Sb1/3O2 slabs of edge sharing octahedra. Each SbO6 octahedron is surrounded by LiO6 and FeO6 octahedra creating a honeycomb arrangement within the slabs. Powder X-ray diffraction indicates the presence of stacking faults. This compound exhibits Curie-Weiss behavior at high temperatures and the effective magnetic moment verifies the presence of high spin Fe3+. The 57Fe Mössbauer spectroscopy confirms Fe3+ in an octahedral position and indicates disorder in the arrangement of LiO6 and FeO6 octahedra in the Li1/3Fe1/3Sb1/3O2 slabs.