Researchers have demonstrated gate-tunable room-temperature ferromagnetism in two-dimensional Fe₃GeTe₂ (FGT) crystals. This discovery opens new possibilities for voltage-controlled magnetoelectronics using atomically thin van der Waals crystals. The study shows that FGT retains itinerant ferromagnetism down to monolayer thickness, with a perpendicular magnetocrystalline anisotropy that protects the magnetic order against thermal fluctuations. In pristine FGT, the ferromagnetic transition temperature (Tc) is suppressed, but an ionic gate significantly raises Tc to room temperature, surpassing the bulk Tc of 205 K. This gate-tunable room-temperature ferromagnetism in FGT offers potential for electrically controlled magnetoelectronic devices. FGT is a layered van der Waals crystal with a unique atomic structure, where Fe₃Ge is sandwiched between Te layers. The material exhibits strong magnetocrystalline anisotropy, which stabilizes long-range ferromagnetic order in monolayers. The study also reveals a strong dimensionality effect on ferromagnetism, with Tc decreasing as the number of layers decreases. The critical layer number (N₀) for the transition from 3D to 2D magnetism was determined to be approximately 3.2, and the critical exponent (λ) was found to be around 1.7. The researchers developed a novel exfoliation method using Al₂O₃ to isolate monolayer FGT from bulk crystals. They then fabricated devices and measured magnetotransport properties, including the anomalous Hall effect (AHE), which allowed them to determine Tc and study the evolution of magnetic order. The results show that FGT exhibits a large AHE, indicating strong spin-orbit coupling and itinerant ferromagnetism. By applying an ionic gate, the researchers achieved room-temperature ferromagnetism in FGT thin flakes, with Tc reaching up to 300 K. The gate-induced modulation of Tc was accompanied by significant changes in coercivity, demonstrating the potential for voltage-controlled magnetoelectronics. The study also shows that the gate can induce substantial changes in the electronic structure of FGT, leading to sharp peaks in the density of states (DOS) at the Fermi level, which contribute to the increase in Tc. The findings highlight the unique properties of FGT as a two-dimensional itinerant ferromagnet, with high Tc and large perpendicular anisotropy, making it a promising candidate for room-temperature spintronic applications. The study provides a new model system for exploring 2D itinerant ferromagnetism and could lead to the development of ultra-high density, gate-tunable magnetoelectronic devices based on FGT.Researchers have demonstrated gate-tunable room-temperature ferromagnetism in two-dimensional Fe₃GeTe₂ (FGT) crystals. This discovery opens new possibilities for voltage-controlled magnetoelectronics using atomically thin van der Waals crystals. The study shows that FGT retains itinerant ferromagnetism down to monolayer thickness, with a perpendicular magnetocrystalline anisotropy that protects the magnetic order against thermal fluctuations. In pristine FGT, the ferromagnetic transition temperature (Tc) is suppressed, but an ionic gate significantly raises Tc to room temperature, surpassing the bulk Tc of 205 K. This gate-tunable room-temperature ferromagnetism in FGT offers potential for electrically controlled magnetoelectronic devices. FGT is a layered van der Waals crystal with a unique atomic structure, where Fe₃Ge is sandwiched between Te layers. The material exhibits strong magnetocrystalline anisotropy, which stabilizes long-range ferromagnetic order in monolayers. The study also reveals a strong dimensionality effect on ferromagnetism, with Tc decreasing as the number of layers decreases. The critical layer number (N₀) for the transition from 3D to 2D magnetism was determined to be approximately 3.2, and the critical exponent (λ) was found to be around 1.7. The researchers developed a novel exfoliation method using Al₂O₃ to isolate monolayer FGT from bulk crystals. They then fabricated devices and measured magnetotransport properties, including the anomalous Hall effect (AHE), which allowed them to determine Tc and study the evolution of magnetic order. The results show that FGT exhibits a large AHE, indicating strong spin-orbit coupling and itinerant ferromagnetism. By applying an ionic gate, the researchers achieved room-temperature ferromagnetism in FGT thin flakes, with Tc reaching up to 300 K. The gate-induced modulation of Tc was accompanied by significant changes in coercivity, demonstrating the potential for voltage-controlled magnetoelectronics. The study also shows that the gate can induce substantial changes in the electronic structure of FGT, leading to sharp peaks in the density of states (DOS) at the Fermi level, which contribute to the increase in Tc. The findings highlight the unique properties of FGT as a two-dimensional itinerant ferromagnet, with high Tc and large perpendicular anisotropy, making it a promising candidate for room-temperature spintronic applications. The study provides a new model system for exploring 2D itinerant ferromagnetism and could lead to the development of ultra-high density, gate-tunable magnetoelectronic devices based on FGT.