Competing interactions in the quasi-2D heavy fermion Ce₂RhIn₈

The heavy fermion family Ce_nMIn_3n+2 (M = Co, Rh, In with n = 1,2…∞) consists of n layers of CeIn₃ stacked along the c-axis, with a spacer layer of MIn₂. This allows for a discrete tuning of the electronic structure from quasi-2D (n = 1) to fully 3D (n = ∞). The n = 2 compound Ce₂RhIn₈ forms an important member of the family with intermediate dimensionality. Here, we use time-of-flight neutron scattering to probe the magnetic interactions in Ce₂RhIn₈ in order to probe the effect of reduced dimensionality on the magnetic coupling. We find a canted antiferromagnetic structure with a moment size comparable to what is seen for CeRhIn₅. Furthermore, we find quasi-elastic scattering that may be the result of the competition between 2D and 3D characteristics.