title: Oxygen-driven competition between low-dimensional structures of Sr3CoMO6 and Sr3CoMO7-δ with M = Ru, Ir.
abstract: We have realized a reversible structure transformation of one-dimensional 1D K4CdCl6-type Sr3CoMO6 with the Co(2+)/M(4+) cation ordering into the two-dimensional 2D double layered Ruddlesden-Popper structure Sr3CoMO7-δ with a random distribution of Co and M (with M = Ru, Ir) upon increasing the partial oxygen pressure. The combined soft and hard X-ray absorption spectroscopy studies show that under transformation, Co and M cations were oxidized to Co(3+) and M(5+). During oxidation, high-spin Co(2+) in Sr3CoMO6 first transforms into high-spin Co(3+) in oxygen-deficient Sr3CoMO7-δ, and then further transforms into low-spin Co(3+) in fully oxidized Sr3CoMO7 upon further increasing the partial pressure of oxygen. The 1D Sr3CoMO6 compound is magnetically ordered at low temperatures with the magnetic moments lying along the c-axis. Their alignment is parallel for Sr3CoRuO6 and antiparallel for Sr3CoIrO6. The 2D compounds reveal a spin-glass-like behavior related to the random distribution of magnetic cations in the structure.
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden, Germany. Daria.Mikhailova@cpfs.mpg.de.
authors.forename: Daria
authors.initials: D
authors.lastname: Mikhailova
authors.forename: Phillip
authors.initials: P
authors.lastname: Reichel
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Tsirlin
authors.forename: Artem M
authors.initials: AM
authors.lastname: Abakumov
authors.forename: Anatoliy
authors.initials: A
authors.lastname: Senyshyn
authors.forename: Kailash M
authors.initials: KM
authors.lastname: Mogare
authors.forename: Marcus
authors.initials: M
authors.lastname: Schmidt
authors.forename: Chang-Yang
authors.initials: CY
authors.lastname: Kuo
authors.forename: Chin-Wen
authors.initials: CW
authors.lastname: Pao
authors.forename: Tun-Wen
authors.initials: TW
authors.lastname: Pi
authors.forename: Jyh-Fu
authors.initials: JF
authors.lastname: Lee
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Hu
authors.forename: Liu Hao
authors.initials: LH
authors.lastname: Tjeng