The synthesis of some transition metal SrIr 1Àx M x O 3 type oxides is described. These have an orthorhombic perovskite type-structure and are only found when the formal oxidation state of the Ir is approximately equal to +4.5 and for M ¼ Fe, Co, Ni and Zn. Occupancy of the TM e g type orbitals appears to contribute to the break-down of the dimeric motif seen in the 6H-SrIrO 3 structure. Variable temperature resistivity measurements show that SrIr 0.8 Zn 0.2 O 3 is a metal; SrIr 0.8 Ni 0.2 O 3 an non-metal and SrIr 0.8 Co 0.2 O 3 undergoes a temperature dependent metal-insulator transition.

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High resolution powder neutron diffraction measurements on polycrystalline SrSnO3 between 8 and 350 K are described. SrSnO3 retains the orthorhombic Pbnm structure over this temperature range. Examination of the thermal expansion of the individual lattice parameters reveals an anomaly near 230 K that may reflect the presence of polar nanodomains associated with local disorder of the octahedral tilts.

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