Etude de la structure cristallographique et magnetique de Cu2FeGeS4 et remarque sur la structure magnetique de Cu2MnSnS4

Single crystal X ray diffraction shows that synthetic briartite Cu₂FeGeS₄ belongs to space group I 4̄ 2 m. Powder neutron diffraction allows the determination of the propagation vector $\text{k}$ and of some features of the magnetic structure. $\text{k}\text{=}\text{1}\text{2}\text{O}\text{1}\text{2}\text{]}$ as in Cu₂MnSnS₄. The degeneracies of the magnetic structures compatible with observations are discussed.