Abstract

The crystal structure, and magnetic and magnetocaloric properties of rapidly solidified Ni0.895Cr0.105MnGe1.05 melt-spun ribbons is reported. The ribbon samples crystallize into a single-phase hexagonal Ni2In-type structure at room temperature. The as-quenched ribbons showed a second order magnetic transition at 192 +/- 1 K at mu H-o = 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 similar to 245 +/- 1K). The annealed ribbons undergo a first-order magnetostructural transition (MST) with a large maximum reversible magnetic entropy change of Delta S-M = 16.1 J kg(-1)K(-1) (this is about a fourfold increase compared to the Delta S-M observed for the bulk sample of the same nominal composition) and RC = 144 J kg(-1) for mu(o)Delta H = 5 Tat temperature T = T-M similar to 245 +/- 1 K. The increase in the Delta 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 Delta S-M at the MST illustrates the potential of Ni0.895Cr0.105MnGe1.05 ribbons for magnetic cooling technology.