title: Magnetic structure of the kagome mixed compound (Co(0.5)Ni(0.5))(3)V(2)O(8).
abstract: We report the magnetic structure of (Co(0.5)Ni(0.5))(3)V(2)O(8) (CNVO) deduced by single crystal neutron diffraction. This compound exhibits features which differ from that of its parent compounds, which are absolutely collinear along the a axis for Co(3)V(2)O(8) (CVO) or exhibit magnetic moments predominantly in the a-b plane with small components along c in the case of Ni(3)V(2)O(8) (NVO). The averaged magnetic moments of the statistically distributed Ni(2+) and Co(2+) ions in CNVO are oriented in the a-c plane and form loops of quasiferromagnetically coupled spins. These loops are connected along the a axis and separated along the c axis by cross-tie spins forming a quasiferromagnetic wave with the upper part of the respective neighbouring loops. The magnetic moments are sinusoidally modulated by the propagation vector k = (0.49,0,0) with an average amplitude of 1.59(1) μ(B) for a magnetic ion on a cross-tie site and 1.60(1) μ(B) for the spine site. In addition to neutron diffraction, specific heat and magnetization data, which confirm that the only magnetic phase transition above 1.8 K is the onset of antiferromagnetic order at T(N) = 7.4(1) K, are presented.
authors.affiliation: Institute for Materials Science, University of Technology, D-64287 Darmstadt, Germany. Institut Max von Laue-Paul Langevin, 38042 Grenoble Cedex 9, France.
authors.forename: N
authors.initials: N
authors.lastname: Qureshi
authors.forename: H
authors.initials: H
authors.lastname: Fuess
authors.forename: H
authors.initials: H
authors.lastname: Ehrenberg
authors.forename: B
authors.initials: B
authors.lastname: Ouladdiaf
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez-Carvajal
authors.forename: T C
authors.initials: TC
authors.lastname: Hansen
authors.forename: Th
authors.initials: T
authors.lastname: Wolf
authors.forename: C
authors.initials: C
authors.lastname: Meingast
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: W
authors.initials: W
authors.lastname: Knafo
authors.forename: H V
authors.initials: HV
authors.lastname: Löhneysen