Orbital Bi-Stripes in High Doped Bilayer Manganites

Abstract

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 wavevectors of (h+-δ,k+-δ,l) and (h+-2δ,k+-2δ,l), arising from orbital ordering with associated Jahn-Teller distortions and charge ordering respectively. We observe a phase transition 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 wavevector and correlation. We attribute this to a new orbital bi-stripe phase, accompanied by weak, frustrated, charge ordering. The observed azimuthal dependence of the orbital order reflections supports the model proposed for this new phase.

arXiv comment8 pages, 9 figures

References in corpus (13)

• Orbital ordering, Jahn-Teller distortion, and anomalous X-Ray scattering in Manganates
• "Wigner crystal" and "stripe" models for the magnetic and crystallographic superstructures of La0.333Ca0 .667MnO3
• Direct observation of orbital ordering in La${}_{0.5}$Sr${}_{1.5}$MnO${}_4$ using soft x-ray diffraction
• Theory of Anomalous X-ray Scattering in Orbital Ordered Manganites
• Interplay of spin and orbital ordering in the layered colossal magnetoresistance manganite La2-2xSr1+2xMn2O7 (0.5<=x<=1.0)
• Elastic interaction and superstructures in manganites and other Jahn-Teller systems
• Temperature dependent changes of the Mn 3d and 4p bands near T${}_c$ in Colossal Magnetoresistance systems: a XANES study of La${}_{1-x}$Ca${}_x$MnO${}_3$
• Stripes Induced by Orbital Ordering in Layered Manganites
• Orbital Ordering in the Manganites :- Resonant X-ray Scattering Predictions at the Manganese L_II and L_III Edges
• Nature of $e_g$ Electron Order in La${}_{1-x}$Sr${}_{1+x}$MnO${}_4$
• Continuous Charge Modulated Diagonal Phase in Manganites
• Evidence for nano-scale inhomogeneities in bilayer manganites in the Mn\sp{4+} rich region: $0.54\le \mathbf{x}\le 0.80$
• Magnetic and orbital order in overdoped bilayer manganites

Cited by in corpus (6)

• Neutron scattering studies on stripe phases in non-cuprate materials
• Doping dependence of spin and orbital correlations in layered manganites
• Evidence for charge orbital and spin stripe order in an overdoped manganite
• Soft vibrational mode associated with incommensurate orbital order in multiferroic CaMn${}_7$O${}_{12}$
• Evidence of photo-induced dynamic competition of metallic and insulating phase in a layered manganite
• Dynamics of bi-stripes and a colossal metal-insulator transition in the bi-layer manganite La${}_{2-2x}$Sr${}_{1+2x}$Mn${}_2$O${}_7$ (x~0.59)