The critical properties of the single-crystalline semiconducting ferromagnet
CrGeTe3​ were investigated by bulk dc magnetization around the paramagnetic
to ferromagnetic phase transition. Critical exponents β=0.200±0.003
with critical temperature Tc​=62.65±0.07 K and γ=1.28±0.03
with Tc​=62.75±0.06 K are obtained by the Kouvel-Fisher method whereas
δ=7.96±0.01 is obtained by the critical isotherm analysis at Tc​=62.7 K. These critical exponents obey the Widom scaling relation δ=1+γ/β, indicating self-consistency of the obtained values. With these
critical exponents the isotherm M(H) curves below and above the critical
temperatures collapse into two independent universal branches, obeying the
single scaling equation m=f±​(h), where m and h are renormalized
magnetization and field, respectively. The determined exponents match well with
those calculated from the results of renormalization group approach for a
two-dimensional Ising system coupled with long-range interaction between spins
decaying as J(r)≈r−(d+σ) with σ=1.52