Large reversible magnetic entropy change in rapidly solidified Ni0.895Cr0.105MnGe1.05 melt-spun ribbons

Abstract The crystal structure, and magnetic and magnetocaloric properties of rapidly solidified Ni 0.895 Cr 0.105 MnGe 1.05 melt-spun ribbons is reported. The ribbon samples crystallize into a single-phase hexagonal Ni 2 In-type structure at room temperature. The as-quenched ribbons showed a second order magnetic transition at 192 ± 1 K at μ o H  = 5 mT. A magnetic-field-induced transition from an antiferromagnetic (AFM)-like to a ferromagnetic (FM) state of martensite structure was observed in annealed ribbons below the temperature of the martensitic transformation ( T M  ∼ 245 ± 1 K). The annealed ribbons undergo a first-order magnetostructural transition (MST) with a large maximum reversible magnetic entropy change of Δ S M  = 16.1 J kg −1  K −1 (this is about a four-fold increase compared to the Δ S M observed for the bulk sample of the same nominal composition) and RC  = 144 J kg −1 for μ o Δ H  = 5 T at temperature T  =  T M  ∼ 245 ± 1 K. The increase in the Δ S M peak value leads to an improved RC compared to that of the bulk sample (122 J kg −1 ). The observed MCE and quasi-reversible character of Δ S M at the MST illustrates the potential of Ni 0.895 Cr 0.105 MnGe 1.05 ribbons for magnetic cooling technology.