Investigation of Magnetocaloric Properties and Critical Behavior in Layered Type (Ce<inf>0.65</inf>La<inf>0.35</inf>)Mn<inf>2</inf>Ge<inf>2</inf>Room Temperature Ferromagnet

The quaternary (Ce0.65La0.35)Mn2Ge2 has been prepared by arc melting route from a low-cost misch metal (Ce0.65La0.35) and its magnetic and magnetocaloric properties have been evaluated. (Ce0.65La0.35)Mn2Ge2 belonging to body-centered tetragonal (BCT) structure of space group of I4/mmm exhibits a second-order transition from ferro to antiferromagnetic at 320 K. The field-dependent magnetization confirms the ferromagnetic nature below Curie temperature (320 K), showing the magnetization of 32 eμg and the coercivity of 5.3 kOe at 10 K. The isothermal magnetic entropy change (Δ SM) has been determined around transition temperature (TC) at various applied fields and the maximum -Δ SM values are found to be 0.76-2.09 J/kg ·K at an applied field of 10-50 kOe. The corresponding relative cooling power (RCP) values are 13-63 J/kg. The modified Arrott plots and field- and temperature-dependent magnetization in the vicinity of ferromagnetic-to-antiferromagnetic transition have been used to determine the critical behavior of (Ce0.65La0.35)Mn2Ge2. The values of the associated critical exponents δ, β, and γ are 4.77, 0.36, and 1.36, respectively, which are close to the values of 3-D Heisenberg theory indicating long-range magnetic interaction in (Ce0.65La0.35)Mn2Ge2 compound.