摘要：We present a detailed study of structural, magnetic and thermodynamic properties of a series of Heusler alloys Fe 2-x Mn x CrAl (x = 0, 0.25, 0.5, 0.75 and 1). Structural investigation of this series is carried out using high resolution synchrotron X-ray diffraction. Results suggest that with increasing Mn concentration, the L2 1 structure of Fe 2 CrAl is destabilized. The DC magnetization results show a decrement in paramagnetic (PM) to ferromagnetic (FM) phase transition temperature (T C ) with increasing Mn concentration. From the systematic analysis of magnetic memory effect, heat capacity, time dependent magnetization, and DC field dependent AC susceptibility studies it is observed that, Fe 2 CrAl exhibits cluster glass(CG)-like transition approximately at 3.9 K (T f2 ). The alloys, Fe 1.75 Mn 0.25 CrAl and Fe 1.5 Mn 0.5 CrAl exhibit double CG-like transitions near T f1 ~ 22 K, T f2 ~ 4.2 K and T f1 ~ 30.4 K, T f2 ~ 9.5 K respectively, however, in Fe 1.25 Mn 0.75 CrAl, a single CG-like transition is noted at T f2 ~ 11.5 K below T C . Interestingly, FeMnCrAl shows the absence of long ranged magnetic ordering and this alloy undergoes three CG-like transitions at ~22 K (T f * ), 16.6 K (T f1 ) and 11 K (T f2 ). At high temperatures, a detailed analysis of temperature response of inverse DC susceptibility clearly reveals the observation of Griffiths phase (GP) above 300 K (T*) in Fe 2 CrAl and this phase persists with Mn concentration with a decrement in T*.
