${\mathrm{NiS}}_{2-2x}{\mathrm{Se}}_x$ is revisited to determine the magnetic structure using neutron diffraction and magnetic representational analysis. Upon cooling, the insulating parent compound, ${\mathrm{NiS}}_2$, becomes antiferromagnetic with two successive magnetic transitions. The first transition $\left(M1\right)$ occurs at $T_N\sim 39\text{K}$ with ${\mathrm{\Gamma }}_1{\psi }_1$ symmetry and a magnetic propagation vector of $k=\left(000\right)$. The second transition $\left(M2\right)$ occurs at $T_N\sim 30\text{K}$ with $k=(0.5,0.5,0.5)$ and a ${\mathrm{\Gamma }}_1{\psi }_2$ symmetry with face-centered translations, giving rise to four possible magnetic domains. With doping, the system becomes metallic. The transition to the $M2$ state is suppressed prior to $x=0.4$ while the $M1$ state persists. The $M1$ magnetic structure gradually vanishes by $x\sim 0.8$ at a lower concentration than previously reported. The details of the magnetic structures are provided.

• Received 20 April 2015
• Revised 23 November 2015

DOI:https://doi.org/10.1103/PhysRevB.93.024409