Critical behavior of the van der Waals bonded high T C ferromagnet Fe3GeTe2

Abstract

Fe3GeTe2 is a promising candidate for van der Waals bonded ferromagnet because of its high Curie temperature and the prediction that its ferromagnetism can maintain upon exfoliating down to single layer. Here, we have reported the critical behavior to understand its ferromagnetic exchange. Based on various techniques including modified Arrott plot, Kouvel-Fisher plot, and critical isotherm analysis, a set of reliable critical exponents (β = 0.327 ± 0.003, γ = 1.079 ± 0.005, and δ = 4.261 ± 0.009) has been obtained. The critical behavior suggests a three-dimensional long-range magnetic coupling with the exchange distance decaying as J(r) ≈ r −4.6 in Fe3GeTe2. The possible origin of three-dimensional magnetic characteristics in van der Waals bonded magnets is discussed.

Critical behavior of intercalated quasi-van der Waals ferromagnet Fe0.26TaS2

“…As expected, Cr 2 Si 2 Te 6 and Cr 2 Ge 2 Te 6 have β values inside this window and they both demonstrate 2D Ising type coupling [10,11]. While CrI 3 , Fe 3 GeTe 2 , and Mn 3 Si 2 Te 6 are all found to exhibit the 3D critical phenomenon with β > 0.25 [8,9,[46][47][48]. It is interesting that 3D magnetic characteristics are observed in vdW-bonded magnets, and it could be explained by the fact that CrI 3 and Fe 3 GeTe 2 have smaller vdW gaps than Cr 2 Si 2 Te 6 and Cr 2 Ge 2 Te 6 [46,49], which gives rise to much stronger interlayer coupling.…”

“…While CrI 3 , Fe 3 GeTe 2 , and Mn 3 Si 2 Te 6 are all found to exhibit the 3D critical phenomenon with β > 0.25 [8,9,[46][47][48]. It is interesting that 3D magnetic characteristics are observed in vdW-bonded magnets, and it could be explained by the fact that CrI 3 and Fe 3 GeTe 2 have smaller vdW gaps than Cr 2 Si 2 Te 6 and Cr 2 Ge 2 Te 6 [46,49], which gives rise to much stronger interlayer coupling. It is also worth mentioning that Mn 3 Si 2 Te 6 has a similar crystal structure with FTS and that Mn 2 Si 2 Te 6 layers are connected by another Mn atom located inside the interlayer space.…”

Evidence of spin-phonon coupling in CrSiTe3

“…The exfoliation of CrSiTe 3 bulk to a mono and few-layer 2D crystals onto Si/SiO 2 substrate has been achieved [15] with the resistivity between 80 K and 120 K, depending on the number of the layers. Critical exponents for CrSiTe 3 were also determined from theoretical analysis [16].…”

Antisymmetric magnetoresistance in van der Waals Fe 3 GeTe 2 /graphite/Fe 3 GeTe 2 trilayer heterostructures

“…So far, various spintronic devices have been fabricated on the basis of these materials (7)(8)(9)(10)(11)(12)(13)(14)(15). vdW ferromagnetic metal FGT has been studied for many years (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Only very recently, it was realized that nanoflake vdW FGT is a promising vdW ferromagnetic metal for spintronics with a near-square-shaped hys-teresis loop, large coercivity, and perpendicular magnetic anisotropy (16), making it a perfect vdW ferromagnetic metal for spintronic devices (9) and fundamental spintronic research.…”