Magnetic properties of Cs₂IrCl₆single crystals

Cs₂IrCl₆ is a member of cubic antifluorites A₂IrCl₆ (where A is an alkali metal or NH₄) featuring isolated IrCl₆ octahedra arranged on the FCC lattice. This class of material has gained renewed interest recently as a model FCC antiferromagnet with J_eff = ½ involving strong spin-orbit coupling and a combination of Heisenberg and Kitaev exchange interactions [1]. In contrast to K₂IrCl₆, very little work has been done on Cs₂IrCl₆. Here we will present the synthesis and characterization of Cs₂IrCl₆ single crystals. A paramagnetic-to-antiferromagnetic transition was revealed by specific heat and magnetic susceptibility measurements at T_n » 0.5 K. The spin structure was determined by neutron diffraction measurements. We will discuss the magnetic properties of Cs₂IrCl₆ in comparison to other cubic antifluorites in this family.

[1] Nazir Khan, et al, Physical Review B 99, 144425 (2019).