Magnetic Field-Induced Martensitic Phase Transition in Cr-Substituted Ni-Mn-Sb plus B Shape Memory Alloys

In this paper, the Ni50-yCryMn37Sb13 + B-2 (y = 0, 3, 5 and 7) Heusler system was fabricated by the conventional arc-melting method. Samples with low Cr-content (y = 0 and 3) exhibited a mixed phase of 4O and 10 M at room temperature, while the samples with y = 5 and 7 Cr-content crystallized to L2(1) phase with Fm (3) over barm space group. The martensitic transition temperature decreased with increasing Cr-content in the system. The temperature-dependent magnetization results at a magnetic field of 100 Oe revealed an intermartensitic phase transition. The temperature-dependent magnetization measurements under 10(4) Oe (1 T) demonstrated a phase transition from ferromagnetic austenite to weakly magnetic martensite between 300 and 200 K, depending on the substitution level. The presence of hysteresis in the M-H curves confirmed a magnetic field-induced transformation in the samples. The field cooled (FC) M-H hysteresis loops shifted to the negative axis, which indicates exchange bias (EB) effect in the samples. Arrott plots provided evidence for a first-order magnetic phase transition in the fabricated samples.