Reentrant orbital order and the true ground state of LaSr2Mn2O7.
Contrary to conventional wisdom, our purified La 2-2x Sr 1+2x Mn2O7 crystals exhibit CE-type orbital and charge order as the low-temperature ground state for a hole doping level h=0.5. For small deviations from h=0.5, the high-temperature CE phase is replaced at low temperatures by an A-type antiferromagnet without coexistence. Larger deviations result in a lack of CE order at any temperature. Thus, small inhomogeneities in cation or oxygen composition could explain why others commonly see this reentrance with coexistence.
Li
Qing'An
Q
Chinese Academy of Sciences, Beijing, China.
Gray
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Zheng
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Claus
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Rosenkranz
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Ancona
S Nyborg
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Osborn
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Mitchell
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Chen
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Lynn
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