Bibliographic Details
| Title: |
Quasi-two-dimensional magnetism and antiferromagnetic ground state in Li$_2$FeSiO$_4$ |
| Authors: |
Hergett, W., Bouldi, N., Jonak, M., Neef, C., Ritter, C., Abdel-Hafiez, M., Seewald, F., Klauss, H. -H., -Haverkort, M. W., Klingeler, R. |
| Source: |
Phys. Rev. B 111, 024414 (2025) |
| Publication Year: |
2025 |
| Collection: |
Condensed Matter |
| Subject Terms: |
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science |
| More Details: |
Our experimental (neutron diffraction, M\"ossbauer spectroscopy, magnetic susceptibility, specific heat) and numerical studies on the evolution of short- and long-range magnetic order in $\gamma_{\rm II}$-Li\(_2\)FeSiO\(_4\) suggest a quasi-two-dimensional (2D) nature of magnetism. The experimental data obtained on single crystals imply long-range antiferromagnetic order below $T_{\rm N}= 17$~K. A broad maximum in magnetic susceptibility $\chi$ at $T_{\rm m}\simeq 28$~K, observation of magnetic entropy changes up to 100~K and anisotropy in $\chi$ are indicative of low-dimensional magnetism and suggest short-range magnetic correlations up to 200~K. Neutron diffraction shows that long-range antiferromagnetic order is characterised by the propagation vector k=(1/2,0,1/2). The ordered moment $\mu = 2.50(2) \mu_B$ /Fe, at $T = 1.5$~K, is along the crystallographic $a$-axis. This is consistent with the observed static hyperfine field of $B_{\rm hyp}=14.8(3)$\,T by M\"ossbauer spectroscopy which indicates significant orbital contributions. The temperature dependence of $B_{\rm hyp}$ yields the critical exponent $\beta=0.116(12)$ which is in the regime of the 2D Ising behaviour. LSDA+U studies exploiting the experimental spin structure suggest dominating magnetic exchange coupling within the $ac$-layers (i.e., $J_3\simeq -6$~K and $J_6\simeq-2$~K) while interlayer coupling is much smaller and partly frustrated. This confirms the 2D nature of magnetism and is in full agreement with the experimental findings. |
| Document Type: |
Working Paper |
| DOI: |
10.1103/PhysRevB.111.024414 |
| Access URL: |
http://arxiv.org/abs/2501.01758 |
| Accession Number: |
edsarx.2501.01758 |
| Database: |
arXiv |
