Evolution of the 2D antiferromagnetism with temperature and magnetic field in multiferroic Ba${}_2$CoGe${}_2$O${}_7$

Abstract

We report on spherical neutron polarimetry and unpolarized neutron diffraction in zero magnetic field as well as flipping ratio and static magnetization measurements in high magnetic fields on the multiferroic square lattice antiferromagnet Ba${}_2$CoGe${}_2$O${}_7$. We found that in zero magnetic field the magnetic space group is $C{m}^{\prime }m{2}^{\prime }$ with sublattice magnetization parallel to the [100] axis of this orthorhombic setting. The spin canting has been found to be smaller than $0.2^{\circ }$ in the ground state. This assignment is in agreement with the field-induced changes of the magnetic domain structure below 40 mT as resolved by spherical neutron polarimetry. The magnitude of the ordered moment has been precisely determined. Above the magnetic ordering temperature short-range magnetic fluctuations are observed. Based on the high-field magnetization data, we refined the parameters of the recently proposed microscopic spin model describing the multiferroic phase of Ba${}_2$CoGe${}_2$O${}_7$.

References in corpus (15)

• Symmetry breaking due to Dzyaloshinsky-Moriya interactions in the kagome lattice
• Ferroelectricity induced by spin-dependent metal-ligand hybridization in Ba${}_2$CoGe${}_2$O${}_7$
• Giant directional dichroism of terahertz light in resonance with magnetic excitations of the multiferroic oxide BaCo${}_2$Ge${}_2$O${}_7$
• Chirality of Matter Shows Up via Spin Excitations
• Spin-stretching modes in anisotropic magnets: spin-wave excitations in the multiferroic Ba2CoGe2O7
• Non-collinear spin-density wave antiferromagnetism in FeAs
• Spin waves and the origin of commensurate magnetism in Ba2CoGe2O7
• Theory of magnetoelectric resonance in two-dimensional $S=3/2$ antiferromagnet $\mathrm{B}{\mathrm{a}}_2\mathrm{CoG}{\mathrm{e}}_2{\mathrm{O}}_7$ via spin-dependent metal-ligand hybridization mechanism
• Theoretical investigation of magnetoelectric effects in Ba2CoGe2O7
• Multiboson spin-wave theory for Ba2CoGe2O7, a spin-3/2 easy-plane Neel antiferromagnet with strong single-ion anisotropy
• Multiferroic properties of an åkermanite Sr${}_2$CoSi${}_2$O${}_7$ single crystal in high magnetic fields
• Zero and finite temperature mean field study of magnetic field induced electric polarization in Ba2CoGe2O7
• Magnetic structure of RuSr${}_2$GdCu${}_2$O${}_8$ determined by resonant x-ray diffraction
• Low Temperature Dynamics of Magnons in a Spin-1/2 Ladder Compound
• Bond Randomness Induced Magnon Decoherence in a Spin-1/2 Ladder Compound

Cited by in corpus (5)

• Direct observation of spin-quadrupolar excitations in Sr${}_2$CoGe${}_2$O${}_7$ by high field ESR
• Magnetization induced local electric dipoles and multiferroic properties of Ba2CoGe2O7
• Spin Hall magnetoresistance at the altermagnetic insulator/Pt interface
• Magnetic excitations in the noncentrosymmetric magnet Sr2MnSi2O7
• Dipolar-driven mean-field criticality in the ferrimagnet Eu${}_2$MnSi${}_2$O${}_7$