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arXiv · 2310.09268

Magnetic structure, excitations and field induced transitions in the honeycomb lattice $\rm{Er_2Si_2O_7}$

M. Islam·N. d'Ambrumenil·D. D. Khalyavin·P. Manuel·F. Orlandi·J. Ollivier·M. Ciomaga Hatnean·G. Balakrishnan·O. A. Petrenko
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Abstract

We investigate the magnetic properties of the monoclinic D-type $\rm{Er_2Si_2O_7}$ 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 $H \! \parallel \! a$, 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.

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M. Islam, N. d'Ambrumenil, D. D. Khalyavin, P. Manuel, F. Orlandi, J. Ollivier, M. Ciomaga Hatnean, G. Balakrishnan, O. A. Petrenko. 2023-10-13. Magnetic structure, excitations and field induced transitions in the honeycomb lattice $\rm{Er_2Si_2O_7}$. https://doi.org/10.1103/physrevb.109.094420

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