UC Berkeley

Abstract Among many efforts in the research of van der Waals (vdW) magnetic materials, increasing the Curie temperature above room temperature has been at the center of research in developing spintronics technology using vdW materials. Here an effective and reliable method of increasing the Curie temperature of ferromagnetic Fe 3 GeTe 2 vdW materials by Ga implantation is reported. It is found that implanting Ga into Fe 3 GeTe 2 by the amount of 10 −3 Ga Å −3 could greatly enhance the Fe 3 GeTe 2 Curie temperature by almost 100%. Spatially resolved microdiffraction and element‐resolved X‐ray absorption spectroscopy show little changes in the Fe 3 GeTe 2 crystal structure and Fe valence state. In addition, the Ga implantation changes the Fe 3 GeTe 2 magnetization from out‐of‐plane direction at low temperature to in‐plane direction at high temperature. The result opens a new opportunity for tailoring the magnetic properties of vdW materials beyond room temperature.