  Recent studies on weak ferromagnets Fe2-xMnxCrAl (0<x<1) reveal the presence
of cluster glass (CG) and Griffiths phase (GP) below and above the
ferromagnetic transition temperature (TC) [(2019) Sci. Rep. 9 15888]. In this
work, the influence of these inhomogeneous phases on the critical behaviour
(around TC) of the above-mentioned series of alloys has been investigated in
detail. For the parent alloy Fe2CrAl, {\gamma} is estimated as ~ 1.34, which
lies near to ordered 3D Heisenberg model, whereas obtained value of {\beta} ~
0.273 does not belong to any universality class. With increment in Mn
concentration, both exponents {\gamma} and \b{eta} increases, where {\gamma}
and {\beta} approaches disordered 3D Heisenberg model and ordered 3D Heisenberg
model, respectively. The observed deviation in {\gamma} and unconventional
value of {\delta} can be ascribed to the increment in GP with Mn-concentration.
The trend noted for {\beta} can be attributed to the increment in CG regime
with an increase in Mn-content. The self-consistency and reliability of the
estimated exponents are verified by the Widom scaling relation and scaling
equations of state. Our studies indicate that the critical phenomenon of
Fe2-xMnxCrAl (0<x<1) alloys possibly belong to a separate class and is not
described within the framework of any existing universal model.
