Control of structural and magnetic transition in GeNCr₃ by doping manganese ions

As an archetypal antiperovskite nitride compound, GeNCr₃ undergoes a temperature-driven first-order antiferromagnetic-paramagnetic transition at approximately 418 K, accompanied with a structural phase transition from space group P-42₁m to I4/mcm. In this paper, we show that the critical temperature of GeNCr₃ can be tuned from 418 to 240 K by doping manganese ions. Simultaneously, the evolution of the magnetic transition is consistent with the structural transition. Using temperature-dependent X-ray diffraction and X-ray photoelectron spectroscopy, in combination with first-principles calculations, we demonstrate that doping manganese ions tend to occupy the equatorial plane of the nitrogen octahedron.