Synthesis, structure, magnetic properties and structural distortion under high pressure of a new osmate, Sr{sub 2}CuOsO{sub 6}

Journal Article · Sat Mar 15 00:00:00 EDT 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.12.021· OSTI ID:21043933

Gemmill, William R; Mugavero, Samuel J ^[1]; Kim, Seung-Joo ^[2]; Lee, Yongjae ^[3]; Vogt, Thomas; Loye, Hans-Conrad zur ^[1]

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1. Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States)
2. Department of Chemistry, Division of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)
3. Department of Earth System Sciences, Yonsei University, Seoul 120-749 (Korea, Republic of)

A new osmate Sr{sub 2}CuOsO{sub 6} was synthesized and its structure refined using powder synchrotron X-ray diffraction. The results of the Reitveld refinements indicate complete B-cation order in a double perovskite crystal structure. Furthermore, the analysis of the B-cation bond lengths indicates a symmetric coordination around Os, as opposed to a significant distortion of Cu-O bond lengths. The octahedral distortion around Cu(II) is characteristic of a Jahn-Teller distortion. Within the crystal structure of Sr{sub 2}CuOsO{sub 6}, the long Cu-O bonds are aligned in the same direction along the c-axis in the tetragonal unit cell. This parallel arrangement of long Cu-O bonds produces a lattice parameter ratio, c/(2{sup 1/2}a), that is greater than unity. The magnetic susceptibility of Sr{sub 2}CuOsO{sub 6} was measured using a SQUID magnetometer and was observed to be consistent with an assignment of Cu(II)-Os(VI) formal oxidation states, thus confirming the bond valences calculated on the basis of the crystal structure. In perovskites, octahedral tilting and bond shortening are two competing compression mechanisms. Compression mechanisms of this double perovskite were characterized using high-pressure synchrotron X-ray diffraction. Application of hydrostatic pressure up to 6 GPa significantly decreased the lattice parameter ratio, demonstrating the primary compression mechanism is a shortening of the long Cu-O bond. - Graphical abstract: Relative compressibility of the lattice parameters of a new osmate, Sr{sub 2}CuOsO{sub 6}.

• OSTI ID: 21043933
• Journal Information: Journal of Solid State Chemistry, Vol. 181, Issue 3; Other Information: DOI: 10.1016/j.jssc.2007.12.021; PII: S0022-4596(07)00546-4; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BOND LENGTHS
CATIONS
COMPRESSIBILITY
COPPER COMPOUNDS
CUBIC LATTICES
LATTICE PARAMETERS
MAGNETIC SUSCEPTIBILITY
MAGNETOMETERS
OSMIUM COMPOUNDS
OXIDES
PEROVSKITE
PRESSURE RANGE GIGA PA
SQUID DEVICES
STRONTIUM COMPOUNDS
SYNCHROTRONS
SYNTHESIS
X-RAY DIFFRACTION