Magnetic correlations in deuteronium jarosite, a model S = 5/2 Kagomé antiferromagnet

Deuteronium jarosite, (D3O)Fe3(SO4)2(OD)6, contains a Kagome lattice of Heisenberg spins S = 5/2 with a coverage of 97 ± 1%. DC and AC susceptibility measurements show strong in-plane antiferromagnetic exchange (θCW = − 700 ± 5 K) and a spin-glass transition at Tf = 13.8 K, while the magnetic contribution to the specific heat below Tf rises with T as T2, characteristic of two-dimensional propagating modes. Powder neutron diffraction reveals short-range magnetic correlations with a correlation length ξ ≈ 19 ± 2 A at 1.9 K.