${\mathrm{Li}}_2\mathrm{Sr}{\left[\mathrm{MnN}\right]}_2$ single crystals were successfully grown out of Li-rich flux. The crystal structure was determined by single-crystal x-ray diffraction and revealed almost linear $-\mathrm{N}-\mathrm{Mn}-\mathrm{N}-\mathrm{Mn}-$ chains as central structural motif. Tetragonal blocks of air and moisture-sensitive nitridomanganate were employed for electrical transport, heat capacity, and anisotropic magnetization measurements. Both the electronic and magnetic properties are most remarkable, in particular the linear increase of the magnetic susceptibility with temperature that is reminiscent of underdoped cuprate and Fe-based superconductors. Clear indications for antiferromagnetic ordering at $T_N=290$ K were obtained. Metallic transport behavior is experimentally observed in accordance with electronic band structure calculations.

• Received 1 March 2021
• Revised 4 June 2021
• Accepted 21 July 2021

DOI:https://doi.org/10.1103/PhysRevMaterials.5.084407