This paper reports the first experimental discovery of intrinsic long-range ferromagnetic order in pristine Cr₂Ge₂Te₆ atomic layers, a 2D van der Waals (vdW) crystal. The researchers used scanning magneto-optic Kerr microscopy to observe the emergence of ferromagnetic order in bilayer Cr₂Ge₂Te₆ as the temperature decreased, with a clear visibility of thicker flakes indicating a higher critical temperature (Tₖ). The study revealed a strong dimensionality effect, where the transition temperature (Tₖ) increased monotonically with thickness from a bilayer value of ~30 K to a bulk limit of ~68 K. The observed ferromagnetism was attributed to the low-energy magnon excitations in 2D, which are suppressed by thermal fluctuations in 3D. The field dependence of Tₖ was also investigated, showing that a small magnetic field (≤ 0.3 Tesla) could significantly enhance the transition temperature by opening a spin wave excitation gap, in contrast to the stiffness of the transition temperature in 3D systems. The findings provide a close-to-ideal 2D Heisenberg ferromagnet for studying fundamental spin behaviors and open new possibilities for applications such as ultra-compact spintronics.This paper reports the first experimental discovery of intrinsic long-range ferromagnetic order in pristine Cr₂Ge₂Te₆ atomic layers, a 2D van der Waals (vdW) crystal. The researchers used scanning magneto-optic Kerr microscopy to observe the emergence of ferromagnetic order in bilayer Cr₂Ge₂Te₆ as the temperature decreased, with a clear visibility of thicker flakes indicating a higher critical temperature (Tₖ). The study revealed a strong dimensionality effect, where the transition temperature (Tₖ) increased monotonically with thickness from a bilayer value of ~30 K to a bulk limit of ~68 K. The observed ferromagnetism was attributed to the low-energy magnon excitations in 2D, which are suppressed by thermal fluctuations in 3D. The field dependence of Tₖ was also investigated, showing that a small magnetic field (≤ 0.3 Tesla) could significantly enhance the transition temperature by opening a spin wave excitation gap, in contrast to the stiffness of the transition temperature in 3D systems. The findings provide a close-to-ideal 2D Heisenberg ferromagnet for studying fundamental spin behaviors and open new possibilities for applications such as ultra-compact spintronics.