Structural and compositional investigations of Zr4Pt2O: A filled-cubic Ti2Ni-type phase

TitleStructural and compositional investigations of Zr4Pt2O: A filled-cubic Ti2Ni-type phase
Publication TypeJournal Article
Year of Publication2009
AuthorsGupta S, Sordelet DJ, Corbett JD
Journal TitleJournal of Solid State Chemistry
Date Published04/01
ISBN Number0022-4596
Accession NumberISI:000267717600016
Keywordscrystal structure, oxygen, stoichiometry, stuffed ti2ni structure, zone, zr-pt-o system, zr5pt3ox

Syntheses, structural and compositional analyses of the filled cubic Ti2Ni-type phase in Zr-Pt-O system have been studied, largely for the platinum-richer compositions. Diffraction quality Crystals were grown by annealing an arc-melted composition Zr4Pt2O0.66 at 1600 degrees C under Ar. The refined composition Zr4.0Pt1.95(1)O0.93(6) (a = 12.5063(6) angstrom, Fd (3) over barm, Z = 16) is close to the idealized composition Zr4Pt2O known in several other Zr-T-O systems (T = late 4d or 5d transition element). (This composition has been erroneously reported by ICDD for years as Zr6Pt3O (No. 00-017-0557) and referred to as epsilon-Zr6Pt3O.) The product is only marginally poor in platinum and oxygen, in contrast to the 1960 reports of metallographic studies (similar to Zr4Pt1.62O0.44). Under arc-melting conditions, high yields of the cubic phase are obtained from samples with lower platinum concentrations (Zr4Pt1.74O1.04), whereas samples near the refined cubic composition contain hexagonal Zr(5)pt(3)O(x) as well (Mn5Si3-type). The hexagonal structure of binary Zr5Pt3 was also refined (Mn5Si3 type, P6(3)/mcm, a = 8.210(1) angstrom, c = 5.385(2) angstrom) and shown to be non-stoichiometric to at least Zr5Pt2.5. (C) 2009 Elsevier Inc. All rights reserved.

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