Low-temperature Synthesis of Pure-Phase Ti3(Al, Fe)C2 Solid Solution with Magnetic Monoatomic Layers by Replacement Reaction

The formation of the magnetic monoatomic layers in the MAX phases offers atomic-level control over magnetic layered material. The traditional high-temperature solid-phase synthesis method not only has a synthesis temperature as high as 1100 °C but also is easy to produce alloy mesophase impurities. In this work, pure-phase Ti3(Al, Fe)C2 solid solution was successfully synthesized by low-temperature replacement reaction using FeCl2 as the Fe source. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed that the pure-phase Ti3(Al, Fe)C2 solid solution was obtained at 650 °C for 3 h in an argon atmosphere, and the Fe atoms were introduced into the A sites of Ti3AlC2 to form the magnetic monoatomic layers. XRD analysis demonstrated that the formation of alloy mesophases during the synthesis process was avoided by the replacement reaction method. The vibrating sample magnetometer (VSM) test showed that the sample’s saturation magnetization is up to 1.564 emu/g. In this research, a pure MAX phase with magnetic monoatomic layers was obtained at low-temperature for the first time, which has potential applications in the fields of spintronics and current sensors.