Investigation on Phase Transition, Magnetic Property and Magnetocaloric effect in the system Mn₆₀Ga_20-x In_xC₂₀ (x=1, 2, 3, 4, 5) by the partial substitution of In in Ga

We present our findings on the investigation of magnetic properties and magnetocaloric effect of Mn₆₀Ga_20-xIn_xC₂₀ (x= 1, 2, 3, 4, 5) alloys. Our investigations indicates that the system crystallizes in the cubic perovskite structure in space group Pm-3m with the lattice constant of 3.899 Å, which is similar to its parent compound Mn₃GaC (a = 3.896 Å) . The magnetic properties were measured using a MPMS SQUID magnetometer (QUANTUM DESIGN USA). At least, two temperature induced transitions with remarkable magnetic entropy change were observed below 400 K. A transition from antiferromagnetic to ferromagnetic phase (AFM-FM) was observed at low temperatures T_M and a transition from FM to paramagnetic (PM) state at higher temperatures, the Curie temperature (T_c). In addition, we also observed that with increasing ‘x’ the system shows an increase in the Curie temperature and the lattice constants. The M-(H) curves obtained at temperature 10K and field H>10kOe exhibit the typical behavior for ferromagnetic materials. The compound with concentration of x = 4, showed the highest magnetic entropy change (|∆S_M| ₌ 3.1JKg^-1K^-1) and highest Relative Cooling Power (RCP = 245. JKg^-1) at an applied field of ∆H = 50kOe around the Curie temperature (T_C = 249K). Moreover, in the vicinity of transition temperature (T_M) the compound reveal high magnetic entropy change |∆S_M| = 5 JKg^-1K^-1 (x=1) and RCP = 217 JKg^-1 (x=5).