A new nickel(III) oxide family: MSr3NiO6 (M = Sc, In, Tm, Yb and Lu)

The new phases MIIISr3NiIIIO6 have been prepared for M = Sc, In, Tm, Yb and Lu. Thermogravimetric analysis indicates that these phases are stoichiometric nickel(III) oxides. Rietveld refinement of their crystal structures from powder X‐ray diffraction data confirms that they adopt the rhombohedral K4CdCl6‐ type structure (space group R{article}{empty}{document}3{document} c, a = 9.6595 (2) and c = 10.8546 (3) Å for ScSr3NiO6). The M site is fully occupied for M = Sc and In, but a deficiency of scattering for M = Tm, Yb and Lu is shown to be due to Ni substitution through a simultaneous refinement of the YbSr3NiO6 structure using X‐ray and time‐of‐flight neutron diffraction data. The refined composition is (Yb0.83Ni0.17)‐Sr3NiO6. The magnetic susceptibilities of the M = Sc, In and Lu samples show Curie–Weiss behaviour down to 6K; however, ScSr3NiO6 shows a broad transition between 250 and 290 K, with Curie–Weiss behaviour above and below this anomaly. This transition is thought to be between the statically and dynamically Jahn–Teller distorted regimes of octahedrally coordinated, low‐spin Ni3+.