TY  - JOUR
AU  - Ji, W. H.
AU  - Yin, L.
AU  - Zhu, W. M.
AU  - Kumar, C. M. N.
AU  - Li, Cheng
AU  - Li, H.-F.
AU  - Jin, W. T.
AU  - Nandi, S.
AU  - Sun, Xiao
AU  - Su, Y.
AU  - Brückel, Th.
AU  - Lee, Y.
AU  - Harmon, B. N.
AU  - Ke, L.
AU  - Ouyang, Z. W.
AU  - Xiao, Y.
TI  - Noncollinear magnetic structure and anisotropic magnetoelastic coupling in cobalt pyrovanadate Co 2 V 2 O 7g4
JO  - Physical review / B
VL  - 100
IS  - 13
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2019-05267
SP  - 134420
PY  - 2019
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000489820500006
DO  - DOI:10.1103/PhysRevB.100.134420
UR  - https://juser.fz-juelich.de/record/866007
ER  -