title: Frustration of magnetic and ferroelectric long-range order in Bi(2)Mn(4/3)Ni(2/3)O(6).
abstract: The slight incommensurate modulation of the structure of Bi(2)Mn(4/3)Ni(2/3)O(6) is sufficient to suppress the electrical polarization which arises in commensurate treatments of the structure, due to antiferroelectric coupling of local polar units of over 900 A(3). The incommensurate structure is produced by the competition between ferroelectric Bi lone pair-driven A site displacement, chemical order of Mn and Ni on the B site, and both charge and orbital order at these transition metals. The interplay between the frustrated polar Bi displacements and the frustrated spin order at the B site, induced by positional disorder, produces magnetodielectric coupling between the incommensurately modulated lattice and the spin-glass-like ground state with an unusual relationship between the magnetocapacitance and the applied field.
authors.affiliation: Department of Chemistry, University of Liverpool, Robert Robinson Laboratory, Crown Street Liverpool, Liverpool L69 7ZD, UK. j.b.claridge@liverpool.ac.uk
authors.forename: John B
authors.initials: JB
authors.lastname: Claridge
authors.forename: Helen
authors.initials: H
authors.lastname: Hughes
authors.forename: Craig A
authors.initials: CA
authors.lastname: Bridges
authors.forename: Mathieu
authors.initials: M
authors.lastname: Allix
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Suchomel
authors.forename: Hongjun
authors.initials: H
authors.lastname: Niu
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Kuang
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Rosseinsky
authors.forename: Natalia
authors.initials: N
authors.lastname: Bellido
authors.forename: Dominique
authors.initials: D
authors.lastname: Grebille
authors.forename: Olivier
authors.initials: O
authors.lastname: Perez
authors.forename: Charles
authors.initials: C
authors.lastname: Simon
authors.forename: Denis
authors.initials: D
authors.lastname: Pelloquin
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Blundell
authors.forename: Tom
authors.initials: T
authors.lastname: Lancaster
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Baker
authors.forename: Francis L
authors.initials: FL
authors.lastname: Pratt
authors.forename: P Shiv
authors.initials: PS
authors.lastname: Halasyamani