  Heusler alloy Fe2CrAl exhibits a ferromagnetic behaviour below Curie
temperature (TC) ~ 202 K along with presence of cluster glass (CG) phase near
freezing temperature (Tf) ~ 3.9 K and Griffiths phase (GP) above 300 K. The
physical properties of this alloy are very sensitive to substitutions and
anti-site disorder. Here, we investigate the effect of partial substitution of
Mo at Cr-site on physical properties of Fe2CrAl. Structural and morphological
analysis confirms the single cubic structure of the substituted alloys.
Increment in Mo concentration shifts the TC towards lower temperature, which is
ascribed to the effect of increased hybridization strength between 3d-4d states
of Fe/Cr/Mo. Additionally, systematic analysis of AC susceptibility, magnetic
memory effect and time dependent magnetization studies confirm the presence of
CG-like phase near (Tf) ~ 3.5 K in Fe2Cr0.95Mo0.05Al. Such feature gets
suppressed towards lower temperature with an increase of Mo concentration, i.e.
below 1.8 K in Fe2Cr0.85Mo0.15Al. The origin of the glassy signature is
ascribed to the decrement in magnetic anisotropy with Mo concentration. A
partial increment in magnetic entropy change is also noted near TC with the
increase in Mo substitution. Interestingly, at high temperatures (above 350 K),
GP phase persists in both the alloys due to the presence of anti-site disorder.
