We have synthesized off-stoichiometric Ni40Cu10Mn35Ti15 all-d-metal Heusler alloy with a B2 cubic crystal structure by an arc melting process and investigated its structural, magnetic, electronic, thermal, and mechanical properties under the influence of a single-step thermal annealing. The compound exhibits an antiferromagnetic ordering accompanied by thermal hysteresis indicating a first-order magneto-structural transition. Curie–Weiss molecular field analysis reveals the presence of ferromagnetic interactions competing with long-range antiferromagnetic ordering. Thermal annealing leads to the appearance of a heat capacity sharp peak around antiferromagnetic transition. Electrical resistivity measurements display abrupt changes close to the magneto-structural transition revealing the strong coupling among spin, lattice, and charge degrees of freedom characteristic of a martensitic transition (MT). We have also evaluated its mechanical properties from microhardness measurements, and the results indicate that this alloy exhibits ductile behavior. The occurrence of MT associated with improved ductility is an essential combination for technological application as shape-memory alloys.

我们合成了非化学计量的Ni 40 Cu 10 Mn 35 Ti 15 all- dB2立方晶体结构的Heusler金属Heusler合金通过电弧熔化工艺进行了研究，并研究了其在单步热退火作用下的结构，磁性，电子，热和机械性能。该化合物表现出反铁磁有序性并伴有热滞现象，表明存在一阶磁结构转变。居里·魏斯分子场分析揭示了铁磁相互作用与远距离反铁磁有序竞争的存在。热退火导致在反铁磁转变附近出现热容尖峰。电阻率测量显示出接近磁结构转变的突然变化，揭示了马氏体转变（MT）的自旋，晶格和电荷自由度之间的强耦合。我们还通过显微硬度测量评估了其机械性能，结果表明该合金具有延展性。与延展性提高相关的MT的出现是技术应用中形状记忆合金的必要组合。