%0 Journal Article
%A Ji, W. H.
%A Yin, L.
%A Zhu, W. M.
%A Kumar, C. M. N.
%A Li, Cheng
%A Li, H.-F.
%A Jin, W. T.
%A Nandi, S.
%A Sun, Xiao
%A Su, Y.
%A Brückel, Th.
%A Lee, Y.
%A Harmon, B. N.
%A Ke, L.
%A Ouyang, Z. W.
%A Xiao, Y.
%T Noncollinear magnetic structure and anisotropic magnetoelastic coupling in cobalt pyrovanadate Co 2 V 2 O 7g4
%J Physical review / B
%V 100
%N 13
%@ 2469-9950
%C Woodbury, NY
%I Inst.
%M FZJ-2019-05267
%P 134420
%D 2019
%X Co2V2O7 was recently reported to exhibit remarkable magnetic-field-induced magnetization plateaus and ferroelectricity [R. Chen et al., Phys. Rev. B 98, 184404 (2018)], but its magnetic ground state remains ambiguous. Magnetometry measurements and time-of-flight neutron powder diffraction (NPD) have been employed to study the structural and magnetic properties of Co2V2O7, which includes two nonequivalent Co sites. Upon cooling below the Néel temperature TN=6.0(2) K, we observe magnetic Bragg peaks at 2 K in NPD, which indicates the formation of long-range magnetic order of Co2+ moments. After symmetry analysis and magnetic structure refinement, we demonstrate that Co2V2O7 possesses a complicated noncollinear magnetic ground state with Co moments mainly located in the b-c plane and forming a noncollinear spin-chain-like structure along the c-axis. The ab initio calculations demonstrate that the noncollinear magnetic structure is more stable than various ferromagnetic states at low temperature. The noncollinear magnetic structure with a canted ↑↑↓↓ spin configuration is considered to be the origin of magnetoelectric coupling in Co2V2O7 because the inequivalent exchange striction induced by the spin-exchange interaction between the neighboring spins could be the driving force of ferroelectricity. It is also found that the deviation of lattice parameters a and b is opposite below TN, while the lattice parameter c and β stay almost constant below TN, evidencing the anisotropic magnetoelastic coupling in Co2V2O7.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000489820500006
%R 10.1103/PhysRevB.100.134420
%U https://juser.fz-juelich.de/record/866007