Coupled spin-1/2 antiferromagnetic chain Cs2LiRuCl6 with partially disordered crystal lattice
Abstract
We determined the crystal structure of Cs2LiRuCl6, which was synthesized first in this work, and investigated its magnetic properties. Cs2LiRuCl6 has a hexagonal structure composed of linear chains of face-sharing RuCl6 and LiCl6 octahedra. In two-thirds of the structural chains, Ru3+ and Li+ sites are almost ordered, while in the other chains their sites are disordered. This situation is analogous to the ground state of the antiferromagnetic Ising model on a triangular lattice. Using electron paramagnetic resonance, we evaluated the g factors of Ru3+ with effective spin-1/2 as gc\,=\,2.72 and gab\,=\,1.50 for magnetic fields H parallel and perpendicular to the c axis, respectively. Magnetization curves for H\,\,c and H\,\,c are highly anisotropic. However, these magnetization curves approximately coincide when normalized by the g factors. It was found from the magnetization and specific heat results that Cs2LiRuCl6 can be described as a coupled one-dimensional S\,=\,1/2 Heisenberg-like antiferromagnet with J/k B\,\,3.7 K. Three-dimensional ordering occurs at T N\,=\,0.48 K. A magnetic phase diagram for H\,\,c is also presented.