We present the results of a crystallographic analysis, magnetic characterization including neutron powder diffraction, and theoretical assessment of K 2 ReI 6 prepared using solvent reactions. K 2 ReI 6 crystallizes in the space group P2 1 /n with an inversion center. Magnetic measurements of K 2 ReI 6 sample indicate dominant antiferromagnetic coupling with a Curie-Weiss temperature of θ W = -63.3(1) K, effective magnetic moment ∼2.64 μ B /Re but show a weak ferromagnetism ordered at ∼24 K. Neutron powder diffraction indicates long-range order of the Re spins below 24 K, with an ordered magnetic moment of 2.2(1) μ B /Re at 1.5 K. Therefore, a canted antiferromagnetic structure is concluded. The electronic structures using first-principles calculations suggest that the antiferromagnetic model of K 2 ReI 6 yields the lowest total energy and opens a band gap with ∼1.0 eV width, which is consistent with the UV-vis-NIR optical measurements. After including the spin-orbit coupling (SOC) into the calculation, the band degeneracies slightly shift without influencing the band gap. The results imply that K 2 ReI 6 is an antiferromagnetic insulator with weak ferromagnetic spin-canting resulting from strong SOC-entangled ground state S = 3/2.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films