Mn-doping-induced itinerant-electron ferromagnetism in Cr2GeC.

The magnetism of the Mn+1AXn phase, Cr2GeC, and its Mn-doped system, (Cr1−xMnx)2GeC (x≤0.25), synthesized via a solid state reaction, was investigated systematically. Cr2GeC is in a spin-unpolarized state, but the ferromagnetic band polarization is induced immediately by the Mn doping. The Curie temperature, TC, and the spontaneous moment, ps, increase almost proportionally to the Mn concentration, strongly suggesting that Cr2GeC is located in the vicinity of a ferromagnetic quantum critical point. The strong concentration dependence of peff/ps, where peff is the effective moment in the paramagnetic state, indicates that the ferromagnetism appearing in the Mn-doped Cr2GeC can be classified as a typical itinerant-electron ferromagnetism in a wide range of the degree of electron localization. [ABSTRACT FROM AUTHOR]