Thermal-cycling-dependent magnetostructural transitions in a Ge-free system Mn0.5Fe0.5Ni(Si,Al)

Magnetostructural transitions from low-temperature TiNiSi-type phases to high-temperature Ni2In-type phases had been observed in some MnCoGe-based and MnNiGe-based intermetallic systems. In this work, the TiNiSi-to-Ni2In-type magnetostructural transitions, which are associated with large changes in magnetization and large anisotropy lattice distortion, were obtained in a Ge-free system Mn0.5Fe0.5Ni(Si, Al) in the vicinity of room temperature. Thermal-cycling-dependent properties were observed in the as-prepared bulk polycrystalline samples. This phenomenon could be attributed to the presence of anisotropy internal stress and its release by spontaneously cracking across the thermally activated magnetostructural transitions. (C) 2014 AIP Publishing LLC.