Long-range antiferromagnetic ordering in the S= 12 ordered rocksalt oxide Li5OsO6: Comparison with the isoelectronic and isostructural spin glass Li4MgReO6

Li5OsO6 and Li5ReO6 polycrystalline samples were synthesized by conventional solid state methods. Employing powder neutron diffraction data, the crystal structure of Li5OsO6 was reinvestigated. Li5OsO6 crystallizes in C2∕m in an ordered NaCl structure type, where a=5.0472(1)Å, b=8.7827(2)Å, c=5.0079(1)Å, β=109.777(2)° and V=208.90(1)Å3. Magnetic susceptibility and heat capacity data indicate an antiferromagnetic long-range order below 40K, …