J Herrero-Martín et al 2009 J. Phys.: Conf. Ser. 190 012086 doi:10.1088/1742-6596/190/1/012086
J Herrero-Martín1, J García2, G Subías2, J Blasco2, C Mazzoli1 and M C Sánchez2
Show affiliationsThe emergence of superlattice periodicities at metal to insulator transitions in hole doped perovskite oxides responds to a rearrangement of the local atomic structure, and electron and spin density distribution. Originally, the ionic model based on a checkerboard- type atomic distribution served to describe the low temperature charge and orbital ordered (COO) phases arising in half- doped manganites. In the last years, the exploitation of resonant x- ray scattering (RXS) capabilities has shown the need to revisit these concepts and improve the picture. Yet, we have realised that COO is a more common phenomenon than expected that can be observed in a wide range of doping levels. Here we compare the experimental data recently collected by RXS on La0.4Sr1.6MnO4 (x=0.60) and La(Pr)1/3Sr2/3FeO3 (x=0.67). The first shows a COO phase similar to that found in the x=0.5 sample but angular peak positions vs. T denotes the incommensurability of superlattice reflections. Meanwhile, the analysis of the commensurate CO phase in the studied ferrite underlines the role of the structural changes also involving La(Sr) and O atoms.
71.30.+h Metal-insulator transitions and other electronic transitions
Issue 1 (2009)
J Herrero-Martín et al 2009 J. Phys.: Conf. Ser. 190 012086
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