The role of 3d electrons in the appearance of ferromagnetism in the antiferromagnetic Ru2MnGe Heusler compound: a magnetic Compton scattering study

The antiferromagnetism in Ru2MnGe can be suppressed by the substitution of V by Mn and ferromagnetism appears. Synchrotron-based magnetic Compton scattering experiments are used in order to investigates the role of 3d electrons in the indirect/direct exchange interactions for the appearance of ferromagnetism. A small spin moment for the itinerant electron part on the magnetic Compton profile indicates that the metallic ferromagnet Ru2Mn0.5V0.5Ge has a weak indirect exchange interaction between the d-like and sp-like (itinerant) electrons. This suggests that the appearance of ferromagnetism is caused by the enhancement of the direct exchange interactions between d–d electrons in the Ru2MnGe Heusler compound. These findings indicate that the indirect exchange interaction between itinerant electrons and localized electrons is a significant key point for the appearance of ferromagnetism in this system.