Dominance of Electron-Magnon Scattering in Itinerant Ferromagnet Fe3GeTe2

Abstract

Fe3GeTe2 is a 2-dimensional van der Waals material exhibiting itinerant ferromagnetism upto 230 K. Here, we study aspects of scattering mechanism in Fe3Ge2Te2 single crystals via resistivity, magneto-transport and Hall effect measurements. The quadratic temperature dependence of electrical resistivity below the Curie temperature hints towards the dominance of electron-magnon scattering. A non-saturating positive magnetoresistance (MR) is observed at low temperatures when the magnetic field is applied parallel to the sample plane. The linear negative MR at high fields for T < TC corroborates to the suppression in magnon population due to the damping of spin waves. In the high temperature regime T > TC,MR can be described by the scattering from spin fluctuations using the model described by Khosla and Fischer. Isothermal Hall resistivity curves unveil the presence of anomalous Hall resistivity. Correlation between MR and side jump mechanism further reveals that the electron-magnon scattering is responsible for the side jump contribution to the anomalous Hall effect. Our results provide a clear understanding of the role of electron-magnon scattering on anomalous Hall effect that rules out its origin to be the topological band structure