IDENTIFICATION OF A NEW STRONTIUM NI(III) OXIDE PREPARED IN MOLTEN HYDROXIDES

The compound Sr5Ni4O11 was prepared at atmospheric pressure from potassium hydroxide melts, by slow cooling from 700°C. All observed lines in the powder X-ray diffraction pattern were indexed according to a hexagonal unit cell, with a = 9.480(1)Å, c = 7.815(4)Å. The idealized formula Sr5Ni4O11 corresponds to a formal oxidation state of Ni+3. From magnetic susceptibility measurements, the observed high temperature Curie constant is consistent with the low spin t62ge1g configuration. Electrical conductivity measurements exhibit linear behavior of ln ρ{variant} vs 1/T over the range 270-350 K, indicating semiconducting behavior with a bandgap of 0.5 ± 0.1 eV and room temperature resistivity ∼105 Ω-cm. © 1991 Academic Press, Inc.