2023/10/13 by Islam, M., d'Ambrumenil, N., Khalyavin, D. D. +6
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2310.09268
We investigate the magnetic properties of the monoclinic D-type \rmEr2Si2O7 with a distorted honeycomb lattice using powder and single crystal neutron scattering techniques, as well as single crystal magnetisation measurements. The powder neutron diffraction shows that below the ordering temperature, T\rm N=1.85 K, the compound forms a \bf q=0 antiferromagnetic structure with four sublattices. For H ∥ a, magnetisation measurements reveal a narrow, but clearly visible plateau at one third of the magnetisation saturation value. The plateau's stabilisation is accompanied by a significant increase of the magnetic unit cell, as the magnetic peaks with fractional indices are observed in single crystal neutron diffraction experiments. At low-temperatures, the inelastic neutron scattering measurements reveal the presence of low-energy dispersionless excitations. Their spectrum is sensitive to the applied field, it significantly softens on the magnetisation plateau, and demonstrates the behaviour expected for a non-collinear Ising antiferromagnet away from the plateau.