Structural Study of a Hollandite-Type KxIrO2

• Published in: Journal of solid state chemistry Vol. 118; no. 2; pp. 372 - 377
• Main Authors: Bestaoui, N., Deniard, P., Brec, R.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.09.1995; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Inorganic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Water, oxides, hydroxides, peroxides; Inorganic compounds; Ternary compounds; Transition element compounds; Potassium oxides; Iridium oxides; XRD; Experimental study; Crystal structure
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.1995.1356

The new ternary oxide KxIrO2(x ≈ 0.25) was prepared by heating stoichiometric proportions of K2CO3 and pure, chlorine-free IrO2 at 1000°C for 1 hr. The monoclinic cell of the phase corresponds to the following parameters: a = 10.0206(4) Å, b = 3.15268(9) Å, c = 10.0535(4) Å, and β = 90.113(3)°. The Rietveld atomic structure refinement made in the I2/m space group yielded a reliability factor of Rwp = 17.0 and χ2 = 1.19. The structure corresponds to a slight distortion of the well-known hollandite-type structure, with a mean Ir-O distance of 2.03 Å, a value intermediary between that found for Ir(III) and Ir(IV), in agreement with partially reduced iridium in KxIrO2.