Low temperature magnetic properties of a Ni50Mn34In16 ball-milled metamagnetic shape memory alloy

• The effect of the structural disorder induced by a ball milling process on the magnetic properties is analyzed.
• As result, a spin glass state at low temperatures is detected in the corresponding sample with higher ball milling time.
• The analysis of the AC susceptibility dependence with frequency draws to a canonical spin glass state.
• Different annealing treatments give rise to a crystallization process in two stages, first to a disordered B2 structure and afterwards to a L21 structure.

The effect of the atomic disorder induced by ball-milling on the structure and the magnetic properties has been analyzed in a Ni50Mn34In16 metamagnetic shape memory alloy. The as-milled samples displayed an amorphous structure which crystallizes to a disordered B2 structure on annealing. On further annealing, several recovery processes leading to the austenitic L21 structure and the subsequent martensitic transformation are observed. As a result of the recovery processes, the magnetic order drastically varies concurrent with the long-range atomic order. In particular, the magnetism evolves from a frustrated magnetic state compatible with a canonical spin-glass, observed in the amorphous structure, to the well-developed ferromagnetic state.