Compression mechanisms of symmetric and Jahn-Teller distorted octahedra in double perovskites: A2CuWO6 (A 1/4 Sr, Ba), Sr2CoMoO6, and La2LiRuO6
Synchrotron X-ray powder diffraction was used to study the high pressure dependence of the lattice parameter and structural evolution of the monoclinic La{sub 2}LiRuO{sub 6} and tetragonal Sr{sub 2}CoMoO{sub 6}, Sr{sub 2}CuWO{sub 6}, and Ba{sub 2}CuWO{sub 6} double perovskite phases. The c lattice parameters of Sr{sub 2}CuWO{sub 6} and Ba{sub 2}CuWO{sub 6} decreased more rapidly than the a lattice parameters and Ba{sub 2}CuWO{sub 6} exhibited a more anisotropic compression compared to Sr{sub 2}CuWO{sub 6}. Based on lower pressure refinements of Ba{sub 2}CuWO{sub 6}, the anisotropic compression is proposed to be due to the preferential compression of the Cu-O bonds containing cooperative Jahn-Teller distortions aligned parallel to the c-axis, which is in contrast to Sr2CoMoO6, where the change in the octahedral tilting and symmetric bond compression is the prevailing compression mechanism. The bulk moduli were obtained from a fit of the volume-pressure data using the second-order Murnaghan equation of state.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 914044
- Report Number(s):
- BNL-78612-2007-JA; JSSCBI; TRN: US0801498
- Journal Information:
- J. Solid State Chem., Vol. 179; ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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