Extremely large magnetoresistance in high quality magnetic Fe2Ge3 single crystals

Extremely large magnetoresistance (XMR) is typically observed in topological materials as associated with factors such as high mobility carriers and electron-hole compensation. However, its occurrence in magnetic materials is rather rare due to the stability of the electron spin in magnetic fields. In this study, the synthesis of high-quality single crystals of Fe2Ge3 with the highest residual resistivity ratio (RRR = 4778) has allowed to explore its intrinsic magnetic and electrical transport properties, revealing a narrow-gap semiconductor nature with a remarkably high XMR of 2057% at 1.8 K and 12 T. Moreover, Fe2Ge3 exhibits weak ferromagnetism up to room temperature, which is poised to bridge the gap between magnetism and XMR. These findings not only advance our understanding of Fe2Ge3, but also open new avenues for the development of spintronic devices and other technologies based on magnetic semiconductors.