Measurements of the temperature dependence of electrical resistance (R) and neutron powder diffraction (NPD) of a Cr84.7Re15.3 alloy is reported. The magnetism originates from the formation of a spin-density-wave (SDW) as a result of nesting between the electron and hole sheets at the Fermi surface (FS). NPD revealed the magnetic character of the SDW to be commensurate (C) with the lattice with a Néel temperature (TN) of 560 ± 5K that correlates to TN = 585 ± 5K determined from the saddle point in the R(T) results. A power law fit Iα(1−TTN)2β of the neutron data gave β = 0.36(1), indicating that the AF ordering follows the 3D Heisenberg model. An additional antiferromagnetic magnetic contribution, associated with Cr2O3, was observed to co-exist in the alloy. Quantification analyses revealed that the Cr2O3 content was less than 2 wt.%. A β value of 0.30(1) was determined for the magnetic phase transition of Cr2O3 in correspondence with the 3D Ising model.
