Beale, T. A. W. and Spencer, P. D. and Hatton ., P. D. and Wilkins, S. B. and von Zimmermann, M. and Brown, S. D. and Prabhakaran, D. and Boothroyd, A. T. (2005) 'Orbital bi-stripes in highly doped bilayer manganites.', Physical review B., 72 . 064432.
We present high-resolution high-energy and resonant x-ray-diffraction results from La2–2xSr1+2xMn2O7 for x=0.55, 0.575, and 0.60. These compounds show superlattice reflections at wave vectors of (h±,k±,l) and (h±2,k±2,l), arising from orbital ordering with associated Jahn-Teller distortions and charge ordering, respectively. We observe a phase transition boundary between the x=0.55 and x=0.575 doping levels. Samples with x=0.55 display structural characteristics similar to those previously reported for x=0.5. Compared to this the long-range order in samples with x=0.55 and x=0.6 have a distinct change in wave-vector and correlation length. We attribute this to a new orbital bi-stripe phase, accompanied by weak, frustrated, charge ordering. The observed azimuthal dependence of the orbital order reflection supports the model proposed for this new phase.
|Keywords:||X-Ray-Scattering, Layered manganites, Magnetoresistance, Diffraction, Reflections, Crystal, Order.|
|Full text:||PDF - Other (305Kb)|
|Publisher Web site:||http://dx.doi.org/10.1103/PhysRevB.72.064432|
|Publisher statement:||© 2005 by The American Physical Society. All rights reserved.|
|Record Created:||28 Apr 2008|
|Last Modified:||05 Aug 2011 14:27|
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