title: Order by static disorder in the Ising chain magnet Ca3Co2-xMnxO6.
abstract: Ising chain compound Ca3Co2-xMnxO6 exhibits up-up-down-down long-range magnetic order (LRO) in a broad range of 0.75<x<1. The LRO is abruptly lost in the narrow vicinity of x=1, and the magnetic state becomes incommensurate. The commensurate state (but not the LRO) is recovered for larger x. This is surprising because the stoichiometric x=1 state exhibits the best Co/Mn ionic order, and the magnetic LRO appears only in the samples with reduced ionic order. We argue that this "order-by-static-disorder" phenomenon may be related to the disruption of the long-range magnetic interactions by the magnetic-site disorder, reducing magnetic frustration.
authors.affiliation: Department of Physics and Rutgers Center for Emergent Materials, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: V
authors.initials: V
authors.lastname: Kiryukhin
authors.forename: Seongsu
authors.initials: S
authors.lastname: Lee
authors.forename: W
authors.initials: W
authors.lastname: Ratcliff
authors.forename: Q
authors.initials: Q
authors.lastname: Huang
authors.forename: H T
authors.initials: HT
authors.lastname: Yi
authors.forename: Y J
authors.initials: YJ
authors.lastname: Choi
authors.forename: S-W
authors.initials: SW
authors.lastname: Cheong