Tuning of electrical, magnetic, and topological properties of magnetic Weyl semimetal Mn3+xGe by Fe doping.

We report on the tuning of electrical, magnetic, and topological properties of the magnetic Weyl semimetal (Mn3+xGe) by Fe doping at the Mn site, Mn(3+x)-δFeδGe (δ= 0, 0.30, and 0.62). Fe doping significantly changes the electrical and magnetic properties of Mn3+xGe. The resistivity of the parent compound displays metallic behavior, the system withδ= 0.30 of Fe doping exhibits semiconducting or bad-metallic behavior, and the system withδ= 0.62 of Fe doping demonstrates a metal-insulator transition at around 100 K. Further, we observe that the Fe doping increases in-plane ferromagnetism, magnetocrystalline anisotropy, and induces a spin-glass state at low temperatures. Surprisingly, topological Hall state has been noticed at a Fe doping ofδ= 0.30 that is not found in the parent compound or withδ= 0.62 of Fe doping. In addition, spontaneous anomalous Hall effect observed in the parent system is significantly reduced with increasing Fe doping concentration.