Structural effects of cation size variance in magnetoresistive manganese oxide perovskites
- Univ. of Cambridge (United Kingdom)
The structures of La{sub 0.7}Ca{sub 0.11}Sr{sub 0.19}MnO{sub 3}, La{sub 0.32}Pr{sub 0.38}Sr{sub 0.3}MnO{sub 3}, Pr{sub 0.7}Sr{sub 0.23}Ba{sub 0.07}MnO{sub 3}, and Nd{sub 0.7}Sr{sub 0.16}Ba{sub 0.14}MnO{sub 3} have been refined from 4 K powder neutron diffraction data. These samples have all the same doping level and mean A cation size radius, but the A cation size variance {sigma}{sup 2} increases across the series. Cell parameters and coherent and incoherent atomic displacements all change systematically with {sigma}{sup 2}. The largest changes to the MnO{sub 3} framework are in the incoherent structure, and the authors conclude that these are responsible for the strong linear depression of the metal-insulator transition temperature by {sigma}{sup 2}.
- OSTI ID:
- 682134
- Journal Information:
- Chemistry of Materials, Vol. 11, Issue 6; Other Information: PBD: Jun 1999
- Country of Publication:
- United States
- Language:
- English
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