ISSN:
1600-5775
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
The manganese perovskite system La1-xCaxMnO3 displays a complex phase diagram of structural, magnetic, and transport properties with varying Ca concentration. At x = 2/3 and at low temperature, the system is antiferromagnetic with Mn4+ and Mn3+ ions occupying special positions in a charge-ordered supperlattice. The charge ordering transition at about 260 K is characterized by the appearance of satellite peaks around certain strong normal lattice reflections. The normal lattice reflections are due to scattering from planes containing Mn4+ and Mn3+ ions in nearly stoichiometric proportion, however the superlattice reflections are due to scattering from planes containing only Mn4+ ions. By measuring Diffraction Anomalous Fine-Structure spectra on a superlattice reflection and its associated normal lattice reflection, it is possible to isolate absorption-like spectra for the two Mn sites. Due to the weak intensity of these superlattice reflections, we were unable to obtain high quality near-edge spectra for the superlattice reflection measured. However, the data offer useful information about the local electronic structures of the two Mn ions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0909049500017246
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