paper

High antiferromagnetic transition temperature of a honeycomb compound SrRu $_{2}$ O $_{6}$

arXiv:1504.03642 · doi:10.1103/PhysRevB.92.100404

Abstract

The high temperature magnetic order in SrRu $_{2}$ O $_{6}$ was studied by measuring magnetization and neutron powder diffraction with both polarized and unpolarized neutrons. SrRu $_{2}$ O $_{6}$ crystallizes into the hexagonal lead antimonate (PbSb $_{2}$ O $_{6}$ , space group \textit{P} $3$ 1\textit{m}) structure with layers of edge-sharing RuO $_{6}$ octahedra separated by Sr $^{2 +}$ ions. SrRu $_{2}$ O $_{6}$ orders at $T_{N}$ =565\,K with Ru moments coupled antiferromagnetically both in-plane and out-of-plane. The magnetic moment is 1.30(2) $I^¼_{B}$ /Ru at room temperature and is along the crystallographic \textit{c}-axis in the G-type magnetic structure. We performed density functional calculations with constrained RPA to obtain the electronic structure and effective intra- and inter-orbital interaction parameters. The projected density of states show strong hybridization between Ru 4 $d$ and O 2 $p$ . By downfolding to the target $t_{2 g}$ bands we extracted the effective magnetic Hamiltonian. We performed Monte Carlo simulations to determine the transition temperature as a function of inter- and intra-plane couplings and find weak inter plane coupling, 3\% of the intra-plane coupling, permits three dimensional magnetic order at $T_{N}$ . As suggested by the magnetic susceptibility, two-dimensional correlations persist above $T_{N}$ due to the strong intra-plane coupling.

5 pages, 4 figures

High antiferromagnetic transition temperature of a honeycomb compound SrRu2​O6​

Abstract

High antiferromagnetic transition temperature of a honeycomb compound SrRu $_{2}$ O $_{6}$