Resolving the Octahedral Tilt Order in La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub>
ORAL
Abstract
The pattern of tilts of CuO6 octahedra in 214 cuprates can have a large impact on the electronic order. For example, a phase in which the octahedra rotate about the Cu-O bonds is known to pin stripe order in La2-xBaxCuO4. In La2-xSrxCuO4, it has been believed that the octahedral rotations are only about an axis at 45° to the Cu-O bonds. In a recent neutron scattering study of an x = 0.07 crystal, we found evidence that there is also a tilt component about the Cu-O bonds [1]. To further explore the situation, we have performed a crystallographic study of the parent compound, La2CuO4, on the 4-circle diffractometer HB-3A at HFIR (ORNL). While confirming that the crystal has monoclinic symmetry, as previously reported, we have verified a new set of superlattice peaks (hkl) with h and k odd, l even. These reflections are consistent with a tilt component about the Cu-O bonds and require a revision of the space group.
[1] H. Jacobsen et al., Phys. Rev. B 92, 174525 (2015).
[1] H. Jacobsen et al., Phys. Rev. B 92, 174525 (2015).
*Work at BNL supported by Office of Basic Energy Sciences, US DOE, under Contract No. DE-SC0012704.
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Presenters
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John Tranquada
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory
- Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory
- Brookhaven National Laboratory
- Condensed Matter &materials Science, Brookhaven Natl Lab
- Brookhaven Natl Lab
- Brookhaven Natl. Lab