Structure and magnetic properties of new potassium-nickel fluoride-type strontium lanthanum magnesium ruthenium oxide

The crystal structure and magnetic properties of new K2NiF4-type oxides, La2 − 2xSr2xMg1 − xRuxO4(13 ≤ x ≤ 1), have been investigated. Powder X-ray diffraction data were best fitted by the space group I4/mmm, which indicates that the arrangement of Mg2+ and Ru4+ is disordered. An increase in x from 13 first decreased the effective magnetic moment of ruthenium from 3.6 to 3.4 μB then increased it up to 5.0 μB. The tetragonal distortion of (Mg,Ru)O6 octahedra continuously decreased from 1.11 for x = 13 to 1.05 for x = 1.