  Layered van der Waals ferromagnets are promising candidates for designing new
spintronic devices. Here we investigated the critical properties and
magnetocaloric effect connected with ferromagnetic transition in layered van
der Waals VI$_3$ single crystals. The critical exponents $\beta = 0.244(5)$
with a critical temperature $T_c = 50.10(2)$ K and $\gamma = 1.028(12)$ with
$T_c = 49.97(5)$ K are obtained from the modified Arrott plot, whereas $\delta
= 5.24(2)$ is obtained from a critical isotherm analysis at $T_c = 50$ K. The
magnetic entropy change $-\Delta S_M(T,H)$ features a maximum at $T_c$, i.e.,
$-\Delta S_M^{max} \sim$ 2.64 (2.27) J kg$^{-1}$ K$^{-1}$ with out-of-plane
(in-plane) field change of 5 T. This is consistent with $-\Delta S_M^{max}$
$\sim$ 2.80 J kg$^{-1}$ K$^{-1}$ deduced from heat capacity and the
corresponding adiabatic temperature change $\Delta T_{ad}$ $\sim$ 0.96 K with
out-of-plane field change of 5 T. The critical analysis suggests that the
ferromagnetic phase transition in VI$_3$ is situated close to a three- to
two-dimensional critical point. The rescaled $\Delta S_M(T,H)$ curves collapse
onto a universal curve, confirming a second-order type of the magnetic
transition and reliability of the obtained critical exponents.
