title: Reentrant orbital order and the true ground state of LaSr2Mn2O7.
abstract: 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.
authors.affiliation: Chinese Academy of Sciences, Beijing, China.
authors.forename: Qing'An
authors.initials: Q
authors.lastname: Li
authors.forename: K E
authors.initials: KE
authors.lastname: Gray
authors.forename: H
authors.initials: H
authors.lastname: Zheng
authors.forename: H
authors.initials: H
authors.lastname: Claus
authors.forename: S
authors.initials: S
authors.lastname: Rosenkranz
authors.forename: S Nyborg
authors.initials: SN
authors.lastname: Ancona
authors.forename: R
authors.initials: R
authors.lastname: Osborn
authors.forename: J F
authors.initials: JF
authors.lastname: Mitchell
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: J W
authors.initials: JW
authors.lastname: Lynn