Charge ordering and structural distortions at low temperature in La₂-₂ₓSr₁+₂ₓMn₂O₇ (x=0.475 and 0.5)

Wilkins, SB; Spencer, PD; Hatton, PD

Abstract

In this paper we present x-ray scattering results of charge and orbital ordering in the bilayer manganite La222xSr112xMn2O7 with doping levels x50.5 and x50.475. Using high-energy x-ray scattering, the structural modulation due to the Jahn-Teller ordering and the charge ordering due to the Mn31/Mn41 pattern have been measured. Both the x50.5 and x50.475 samples are found to display charge and Jahn-Teller order. We have confirmed that the wave vectors of the Jahn-Teller order, charge order, and orbital order are QW 5(0.25,0.25,0), QW 5(0.5,0.5,0) and QW 5(0.25,0.25,0). The origin of these has been confirmed by resonant x-ray scattering in the vicinity of the Mn K edge using polarization analysis. Contrary to previous studies, the Jahn-Teller order is found to be not reentrant, but is found to reduce in intensity at temperatures below 140 K for both samples. Charge ordering was also detected in the x50.5 sample below this temperature.

Citation

Wilkins, S., Spencer, P., Beale, T., & Hatton, P. (2003). Charge ordering and structural distortions at low temperature in La₂-₂ₓSr₁+₂ₓMn₂O₇ (x=0.475 and 0.5). Physical Review B (Condensed Matter), 67(20), https://doi.org/10.1103/physrevb.67.205110

• Journal Article Type: Article
• Publication Date: 2003-05
• Deposit Date: Jan 9, 2009
• Publicly Available Date: Sep 13, 2010
• Journal: Physical Review B
• Print ISSN: 0163-1829
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 67
• Issue: 20
• DOI: https://doi.org/10.1103/physrevb.67.205110
• Keywords: X-ray-scattering, Giant magnetoresistance, Manganese oxides, l LASR2MN2O7, Manganites, Diffraction, Transition, Beamline, Behavior.
• Public URL: https://durham-repository.worktribe.com/output/1622742