Iron germanium and gallium tellurides

FeₙGeTe₂ (n = 3, 4, 5), Fe₃GaTe₂

Also called Fe₃GeTe₂, Fe₅GeTe₂, Fe₃GaTe₂, FGT

van der Waals crystal magnet

A metallic magnet that can be thinned to a few atomic layers. Its bulk ordering temperature is far higher than that of the magnetic insulators, and with heavy electrical doping thin flakes have reached ferromagnetism at room temperature. Because it conducts, it can carry spin-polarised current directly – which is what spintronic memory needs. Its gallium sibling Fe₃GaTe₂ goes further: it stays ferromagnetic above room temperature without any doping, with its spins held firmly out of the plane.

Cell: Hexagonal, a = 3.94 Å
Atoms per cell: 6
Fe–Te bonds: 2.62 and 2.64 Å
Fe–Fe bonds: 2.55 and 2.61 Å
Fe–Ge bonds: 2.28 and 2.61 Å
Height: 5.24 Å between the outer atom centres

A slab of iron and germanium sandwiched between two sheets of tellurium. In the middle plane, iron and germanium alternate around a honeycomb; above and below the centre of each hexagon sits an iron atom, and the two bond to each other straight through the plane. Real crystals are often missing some of the honeycomb iron, and fewer iron atoms mean a lower Curie temperature – about 220 K in nearly complete crystals, about 150 K in the iron-poor crystal this model was measured on. One layer of Fe_3−xGeTe₂ at 173 K (May and colleagues, Physical Review B 93, 014411, 2016): a = 3.94 Å. About 70% of the honeycomb iron sites were filled in the crystal measured; the model draws them all.

Data sheet

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Kind of sheet: van der Waals crystal
Peels off a layered crystal, one sheet at a time
Behaves as: magnet
Band gap: None – metallic ferromagnet
Thickness: ~0.8 nm per Fe₃GeTe₂ layer
Structure: Fe–Ge or Fe–Ga slabs sandwiched between tellurium layers, van der Waals bonded; hexagonal for Fe₃GeTe₂ and Fe₃GaTe₂
Stability: Air-sensitive: thin flakes oxidise within hours and the surface oxide changes the magnetic anisotropy. Encapsulation is required.
First made: Bulk Fe₃GeTe₂ reported in 2006; atomically thin itinerant ferromagnetism and gate-tuned room-temperature order in 2018 (Fei and colleagues; Deng and colleagues); above-room-temperature Fe₃GaTe₂ in 2022 (Zhang and colleagues)

Compare with other materials

Key properties

Fe₃GeTe₂: bulk Curie temperature of roughly 200–230 K with strong out-of-plane anisotropy; around 130 K in the monolayer
Ionic-liquid gating raised the Curie temperature of thin flakes to room temperature (2018)
Fe₅GeTe₂ orders close to room temperature in bulk
Large anomalous Hall effect and magnetic skyrmions; used in all-van-der-Waals magnetic tunnel junctions
Fe₃GaTe₂: Curie temperature of ~350–380 K with large perpendicular magnetic anisotropy, and hard ferromagnetism reported down to the monolayer

How it is made

Vapour-transport or flux growth of bulk crystals
Mechanical exfoliation in a glovebox
MBE growth of wafer-scale films on GaAs, sapphire or topological insulators
Self-flux growth of Fe₃GaTe₂ crystals, and wafer-scale Fe₃GaTe₂ films

Uses, and how close they are

All-van-der-Waals magnetic tunnel junctions and spin–orbit torque deviceslab
Skyrmion-based memory conceptslab

Readiness runs lab → prototype → pilot → deployed.

Open problems

Fe₃GaTe₂ orders above room temperature without gating – what lifts its Curie temperature so far above Fe₃GeTe₂’s, and can thin layers be made air-stable?
What stabilises skyrmions and other chiral textures in a nominally centrosymmetric crystal – interfaces, defects or dipolar effects?
Can wafer-scale MBE films match the magnetic quality of exfoliated flakes?

Going deeper

Short notes for specialists. Choose a lens in the header and yours comes first.

For theoreticians · your lens

An itinerant ferromagnet with inequivalent iron sites. DFT overestimates moments and Curie temperatures without careful treatment of correlations (DFT+DMFT has been applied), and heavy-fermion-like behaviour has been reported. Strong SOC-driven anisotropy stabilises 2D order; spin textures need micromagnetic models with Dzyaloshinskii–Moriya parameters taken from interfaces or defects.

For experimentalists · your lens

Anomalous Hall hysteresis is the quickest thickness-resolved magnetometry; Kerr microscopy and Lorentz TEM image domains and skyrmions. Iron deficiency lowers the Curie temperature, so check composition by EDS and report it.

For engineers · your lens

The most promising family for room-temperature 2D spintronics: Fe₃GaTe₂ is ferromagnetic above room temperature, and MBE offers a wafer-scale route. Air sensitivity and composition control are the immediate barriers.

In the research tracks

Theory frontiers

Magnetic order in two dimensions

Growth methods

MBE and van der Waals epitaxy

Recent news

The newest items tagged Fe₃GeTe₂, Fe₃GaTe₂, from the news feed updated 5 Oct 2026.

Preprintnot yet peer reviewed 30 Sep 2026 arXiv

Topological Hall Effect Induced by Chiral Spin Textures at the Ferroelectric/Ferromagnetic Interface

Chiral spin textures, largely driven by the Dzyaloshinskii-Moriya interaction, offer significant potential for next-generation computing technologies due to their chirality and topological stability. Ferroelectric/ferromagnetic van der Waals heterostructures are particularly appealing because they can combine…

TheoryFe₃GeTe₂, Fe₃GaTe₂ In₂Se₃

Preprintnot yet peer reviewed 29 Sep 2026 arXiv

Giant orbital Zeeman effects in a magnetic topological van der Waals interphase

Van der Waals (vdW) heterostructures allow the engineering of magnetic and electronic properties via interfacial orbital hybridisation and charge transfer. The resulting electric fields can give rise to Rashba spin-orbit coupling and Dzyaloshinskii-Moriya interactions, which may stabilise novel two-dimensional magnetic…

TheoryGraphene Fe₃GeTe₂, Fe₃GaTe₂

Preprintnot yet peer reviewed 28 Sep 2026 arXiv

Magneto-optical Kerr spectroscopy of exciton Rydberg states in a magnetic van der Waals heterostructure

Excitonic states in two-dimensional semiconductors are sensitive to time-reversal symmetry breaking, yet how interfacial exchange acts on higher-lying exciton Rydberg states remains largely unexplored. Here we show that wavelength-resolved magneto-optical Kerr spectroscopy of a proximity-coupled MoSe₂/Fe₃GaTe₂ van der…

TheoryExperimentFe₃GeTe₂, Fe₃GaTe₂ MoSe₂

Preprintnot yet peer reviewed 15 Sep 2026 arXiv

Gate-tunable magnetic damping in van der Waals Heterostructures

Active control of magnetic damping is a crucial capability for the development of low-power, tunable spintronic devices. In this work, we demonstrate that the intrinsic magnetic damping of 2D materials is highly sensitive to the position of the Fermi level relative to spin-orbit driven anti-crossings, or ``spin hot…

TheoryGraphene Fe₃GeTe₂, Fe₃GaTe₂

Journal 14 Sep 2026 Physical Review B

Suppression of local magnetic moment formation and paramagnetic exchange interactions in monolayer Fe₃GeTe₂

We study the electronic and magnetic properties of monolayer Fe₃GeTe₂ within the density-functional plus dynamical mean-field theory approach in the paramagnetic phase. We argue that this compound is sufficiently far from the local magnetic moment limit, demonstrating n… [Phys. Rev. B 114, 165119] Published Mon Sep 14…

TheoryFe₃GeTe₂, Fe₃GaTe₂

All 16 items tagged Fe₃GeTe₂, Fe₃GaTe₂ in the news feed · RSS feed for Fe₃GeTe₂, Fe₃GaTe₂

Key references

Fe₃GeTe₂ and Ni₃GeTe₂ – two new layered transition-metal compounds: crystal structures, HRTEM investigations, and magnetic and electrical propertiesDeiseroth et al. · European Journal of Inorganic Chemistry 2006, 1561 (2006)cited by 403doi:10.1002/ejic.200501020
Gate-tunable room-temperature ferromagnetism in two-dimensional Fe₃GeTe₂Deng et al. · Nature 563, 94 (2018)cited by 2,639doi:10.1038/s41586-018-0626-9
Two-dimensional itinerant ferromagnetism in atomically thin Fe₃GeTe₂Fei et al. · Nature Materials 17, 778 (2018)cited by 1,538doi:10.1038/s41563-018-0149-7
Above-room-temperature strong intrinsic ferromagnetism in 2D van der Waals Fe₃GaTe₂ with large perpendicular magnetic anisotropyZhang et al. · Nature Communications 13, 5067 (2022)cited by 452doi:10.1038/s41467-022-32605-5