Non-collinear magnetic structure and anisotropic magnetoelastic coupling in cobalt pyrovanadate Co2V2O7

Abstract

The Co2V2O7 is recently reported to exhibit amazing magnetic field-induced magnetization plateaus and ferroelectricity, but its magnetic ground state remains ambiguous due to its structural complexity. Magnetometry measurements, and time-of-flight neutron powder diffraction (NPD) have been employed to study the structural and magnetic properties of Co2V2O7, which consists of two non-equivalent Co sites. Upon cooling below the Neél temperature TN = 6.3 K, we observe magnetic Bragg peaks at 2K in NPD which indicated the formation of long range magnetic order of Co2+ moments. After symmetry analysis and magnetic structure refinement, we demonstrate that Co2V2O7 possesses a complicated non-collinear magnetic ground state with Co moments mainly located in b-c plane and forming a non-collinear spin-chain-like structure along the c-axis. The ab initio calculations demonstrate that the non-collinear magnetic structure is more stable than various ferromagnetic states at low temperature. The non-collinear magnetic structure with canted up-up-down-down spin configuration is considered as the origin of magnetoelectric coupling in Co2V2O7 because the inequivalent exchange striction induced by the spin-exchange interaction between the neighboring spins is the driving force of ferroelectricity. Besides, it is found that the deviation of lattice parameters a and b is opposite below TN, while the lattice parameter c and stay almost constant below TN, evidencing the anisotropic magnetoelastic coupling in Co2V2O7.

arXiv comment9 pages, 8 figures

References in corpus (12)

• Effective Coulomb interaction in transition metals from constrained random-phase approximation
• Quantum criticality and universal scaling of a quantum antiferromagnet
• Step-like magnetization in a spin-chain system: Ca3Co2O6
• Complex magnetic order in the kagome staircase compound Co3V2O8
• Spectroscopic evidence for giant orbital moment and magnetic anisotropy induced by local distortions in alpha-CoV2O6
• Metamagnetism and soliton excitations in the modulated ferromagnetic Ising chain CoV2O6
• Single crystals of the anisotropic Kagome staircase compounds Ni3V2O8 and Co3V2O8
• Spin-orbit transitions in $\alpha$ and $\gamma$-CoV${}_2$O${}_6$
• Magnetic and magnetocaloric properties of quasi-one-dimensional Ising spin chain CoV${}_2$O${}_6$
• Coupled Negative magnetocapacitance and magnetic susceptibility in a Kagome staircase-like compound Co3V2O8
• Magnetization, crystal structure and anisotropic thermal expansion of single-crystal SrEr2O4
• Spin Waves in the Ferromagnetic Ground State of the Kagome Staircase System Co3V2O8

Cited by in corpus (3)

• Structure and magnetic properties of the $S=3/2$ zigzag spin chain antiferromagnet BaCoTe${}_2$O${}_7$
• Crystalline and magnetic structures, magnetization, heat capacity and anisotropic magnetostriction effect in a yttrium-chromium oxide
• Super-Necking Crystal Growth and Structural and Magnetic Properties of SrTb${}_2$O${}_4$ Single Crystals