Electrical control of ferromagnetism in the n-type ferromagnetic semiconductor (In,Fe)Sb with high Curie temperature

By studying the electrical control of the magnetic properties of ferromagnetic semiconductors (FMSs), we can understand many fundamental aspects of carrier-induced ferromagnetism and explore the possibilities of device applications. Previous experiments on the electrical control of ferromagnetism in Mn-doped FMSs were limited to very low temperatures due to their low Curie temperature (TC). Here, we demonstrate electrical control ferromagnetism at high temperature (210 K) in an electric double layer transistor with an n-type high-TC FMS (In0.89,Fe0.11)Sb thin film channel. A liquid electrolyte is used instead of a conventional solid gate to obtain a large change (40%) of the electron density in the (In0.89,Fe0.11)Sb channel. By applying a small gate voltage (0 → +5 V), TC of the (In,Fe)Sb thin film can be changed by 7 K, indicating that the magnetization as well as ferromagnetic phase transition in (In,Fe)Sb can be controlled at high temperature by the gate electric field despite a small change of electron concentration Δn = 2.2 × 1017 cm−3. Our result paves a way for realizing semiconductor spintronic devices operating at room temperature with low power consumption.