Table 1 A summary of the critical exponents of Fe5GeTe2, Fe3-xGeTe2, Cr2Si2Te6, Cr2Ge2Te6 and those predicted by different models (MAP: Modified Arrott plot; KF: Kouvel-Fisher method; CI: critical isotherm analysis).

From: Magnetic critical behavior of the van der Waals Fe5GeTe2 crystal with near room temperature ferromagnetism

Composition

References

Technique

β

γ

δ

{d:n}

J(r)

Fe5GeTe2

This work

MAP

0.351 (1)

1.413 (5)

5.02 (6)

{3:3}

r–4.916

 

This work

KF

0.346 (4)

1.364 (9)

4.94 (0)

  
 

This work

CI

  

5.02 (1)

  

3D Heisenberg

4

Theory

0.365

1.386

4.8

  

3D XY

4

Theory

0.345

1.316

4.81

  

3D Ising

4

Theory

0.325

1.24

4.82

  

Tricritical mean field

5

Theory

0.25

1.0

5

  

Mean field

4

Theory

0.5

1.0

3

  

Fe2.64Ge0.87Te2

12

KF

0.372 (4)

1.265 (1)

4.401 (6)

{3:3}

r–4.89

Fe2.85GeTe2

13

KF

0.363

1.228

4.398

 

r–4.8

Fe3GeTe2

3

KF

0.322 (4)

1.063 (8)

4.301 (6)

 

r–4.6

Cr2Si2Te6

14

KF

0.175 (9)

1.562 (9)

9.925 (5)

{2:1}

r–3.63

Cr2Ge2Te6

15

KF

0.200 (3)

1.28 (3)

7.405

{2:1}

r–3.52