title: Successive spin orderings of tungstate-bridged Li2Ni(WO4)2 of spin 1.
abstract: Magnetic, thermodynamic, and dielectric properties of Li2Ni(WO4)2 of S  =  1 system have been studied using magnetic susceptibility, specific heat, and dielectric constant measurements. The magnetic orderings can be identified in three stages, including a short range magnetic ordering indicated by the rounded χ(T) peak with maximum at  ∼20 K, and signatures of two successful antiferromagnetic long range orderings near T(N1) ~ 18 K and T(N2) ~ 13 K revealed by the d(χ(T)) /d(T) peaks. The successive long range magnetic orderings are related to the quasi triangular symmetry breaking in the ac- and bc-planes and to the change of the dielectric constant, suggesting the presence of spin-phonon coupling. The specific heat and magnetic entropy analysis for Li2Ni(WO4)2 shows the existence of a significant low dimensional magnetic correlations at high temperature and confirms the long range three-dimensional (3D) behavior of magnetic orderings below T(N1) and T(N2).
authors.affiliation: Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: I
authors.initials: I
authors.lastname: Panneer Muthuselvam
authors.forename: R
authors.initials: R
authors.lastname: Sankar
authors.forename: A V
authors.initials: AV
authors.lastname: Ushakov
authors.forename: W T
authors.initials: WT
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Narsinga Rao
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Streltsov
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Karna
authors.forename: L
authors.initials: L
authors.lastname: Zhao
authors.forename: M-K
authors.initials: MK
authors.lastname: Wu
authors.forename: F C
authors.initials: FC
authors.lastname: Chou