Itinerant ferromagnetism induced by electron doping in SrCo2As2.

Abstract It is a fascinating question whether it exists and how to explore Co-based high-temperature superconductors, since Co is next to Fe and has just one more electron than Fe. Based on this, SrCo 2 As 2 has attracted great research interest due to its similar magnetic ground state to Fe-based superconductors. Here, we studied the electron doping effect of SrCo 2 As 2 by doping 2.5% Nd at the Sr sites. Our experimental results show that injecting electrons caused by this doping can induce it from paramagnetism to ferromagnetism. The first-principles calculation indicates that the density of states at the Fermi surface is high enough, which tends to be related to ferromagnetism. This work provides a general strategy for inducing ferromagnetism in Stoner paramagnetic systems. Graphical abstract Unlabelled Image Highlights • Injecting a small amount of electrons induces SrCo 2 As 2 from paramagnetism to ferromagnetism. • The first-principles calculations indicate that SrCo 2 As 2 should be in a critical state between paramagnetism and ferromagnetism. • The crystal structure of Sr 0.975 Nd 0.025 Co 2 As 2 is determined by Rietveld refinement method. • This work provides a general strategy for inducing ferromagnetism in Stoner paramagnetic systems. [ABSTRACT FROM AUTHOR]