Voltage-induced ferromagnetism in a diamagnet

Abstract

Increasingly impressive demonstrations of voltage-controlled magnetism have been achieved recently, highlighting potential for low-power data processing and storage. Magnetoionic approaches appear particularly promising, electrolytes and ionic conductors being capable of on/off control of ferromagnetism and tuning of magnetic anisotropy. A clear limitation, however, is that these devices either electrically tune a known ferromagnet or electrically induce ferromagnetism from another magnetic state, e.g., antiferromagnetic. Here, we demonstrate that ferromagnetism can be voltage-induced even from a diamagnetic (zero-spin) state suggesting that useful magnetic phases could be electrically induced in “nonmagnetic” materials. We use ionic liquid–gated diamagnetic FeS2 as a model system, showing that as little as 1 V induces a reversible insulator-metal transition by electrostatic surface inversion. Anomalous Hall measurements then reveal electrically tunable surface ferromagnetism at up to 25 K. Density functional theory–based modeling explains this in terms of Stoner ferromagnetism induced via filling of a narrow eg band.

Gate-Controlled Magnetic Phase Transition in a van der Waals Magnet Fe5GeTe2

“…However, it is unclear whether the magnetic ground state in F5GT is also sensitive to the in-situ charge doping. Previous experiments demonstrate that magnetism in vdW materials can be controlled by a gate voltage (37)(38)(39)(40), which sheds lights on their applications in vdW spintronics and memory devices. For vdW itinerant magnet, however, conventional electricfield gating is stumbling in the electrical control of the FM, since the electric field tends to be screened within few nano-meters.…”

Comparison of Ferromagnetic Materials: Past Work, Recent Trends, and Applications

“…Ferromagnetism has been induced in LaMnO 3 and SrCoO, which are antiferromagnetic. Recently, ferromagnetism was induced in diamagnetic Fe pyrite ("fool's gold") via the application of voltage [118]. Overall, although ferromagnetic materials have been significantly developed, commercialization of these materials is considerably more time-consuming than their development.…”

Instability of the ferromagnetic quantum critical point in strongly interacting 2D and 3D electron gases with arbitrary spin-orbit splitting

“…Itinerant ferromagnetism in two-dimensional (2D) and three-dimensional (3D) electron gas has been observed in various materials, such as manganese perovskites [1][2][3][4], transition-metal-doped semiconductors [5][6][7], monolayers of transition metal dichalcogenides [8][9][10][11][12], and many others [13][14][15][16][17][18][19][20]. The physical mechanisms leading to the ferromagnetic ground state depend strongly on the materials.…”