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arXiv · 1101.5943

Complex room temperature ferrimagnetism induced by zigzag oxygen-vacancy stripes in Sr3YCo4O10.72

D. D. Khalyavin·L. C. Chapon·E. Suard·J. E. Parker·S. P. Thompson·A. A. Yaremchenko·V. V. Kharton
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Abstract

The high temperature ferromagnetism in Sr3YCo4O10+delta perovskite, whose origin has been the subject of a considerable debate, has been studied by neutron powder diffraction and synchrotron X-ray diffraction measurements. Oxygen vacancy ordering creates a complex pattern of zigzag stripes in the oxygen-deficient CoO4+delta layers, where the Co ions are found in three distinct coordinations. The symmetry of this unprecedented structural modulation, in conjunction with the existence of different Co spin states, provide a straightforward explanation for the appearance of ferrimagnetism. A model for the magnetic structure compatible with these structural features is proposed, based on the refinement of powder neutron data. The macroscopic moment as a function of temperature that can be calculated from the values of the ordered spins extracted from refinements, is in excellent agreement with bulk magnetization. Unlike previous models, a collinear G-type magnetic structure with uncompensated moments due to distinct spin-states of Co imposed by different coordination is found.

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D. D. Khalyavin, L. C. Chapon, E. Suard, J. E. Parker, S. P. Thompson, A. A. Yaremchenko, V. V. Kharton. 2011-01-31. Complex room temperature ferrimagnetism induced by zigzag oxygen-vacancy stripes in Sr3YCo4O10.72. https://doi.org/10.1103/physrevb.83.140403

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