Synthesis and structural studies of the transition-metal-doped Rh perovskites LaMn0.5Rh0.5O3 and LaCu0.5Rh0.5O3

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Date
2010-03-09
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Journal ISSN
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Publisher
American Chemical Society
Abstract
The two orthorhombic perovskites LaMn0.5Rh0.5O3 and LaCu0.5Rh0.5O3 have been characterized using X-ray absorption near edge structure (XANES) measurements and powder synchrotron X-ray and neutron diffraction. The Mn and Rh in LaMn0.5Rh0.5O3 are essentially trivalent and disordered onto the same crystallographic site. The absence of an appreciable Jahn−Teller (JT) distortion of the BO6 octahedra is a consequence of this disorder and large magnitude of the octahedral tilting. XANES measurements show that the Rh in LaCu0.5Rh0.5O3 has a valence state of around +3.5 as a consequence of extensive charge delocalization between the Cu and Rh cations, that are also disordered onto a single site. These two effects combine to further reduce the distortion of the octahedra in LaCu0.5Rh0.5O3 relative to that of LaMn0.5Rh0.5O3. © 2010, American Chemical Society
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Keywords
Perovskites, Rhodium, Absorption, Doped materials, Jahn-Teller effect, X-ray diffraction
Citation
Ting, J., Kennedy, B. J., Zhang, Z., Avdeev, M., Johannessen, B., & Jang, L. Y. (2010). Synthesis and structural studies of the transition-metal-doped Rh perovskites LaMn0.5Rh0.5O3 and LaCu0.5Rh0.5O3. Chemistry of Materials, 22(5), 1640-1646. doi:10.1021/cm902718r
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