Details

Autor(en) / Beteiligte

• Li, Jianqiang
• Bai, Songwei
• Liu, Heyan
• Luo, Hongzhi
• Meng, Fanbin

Titel

Effect of Cu doping on crystal structure, martensitic transformation, and magnetic properties of Mn2NiGa1−xCux (x = 0–0.7) ribbons

Ist Teil von

• Applied physics letters, 2023-10, Vol.123 (17)

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2023

Quelle

AIP Journals (American Institute of Physics)

Beschreibungen/Notizen

• Magnetic shape memory alloys Mn2NiGa1−xCux (x = 0–0.7) melt-spun ribbons were synthesized, and their crystal structure, martensitic transformation, and magnetic and transport properties were studied. In Mn2NiGa1−xCux, unusual composition dependences of these properties were observed: the lattice parameter increases with Cu-doping, though Cu has a smaller atomic radius compared with Ga. The martensitic transformation temperature decreases with increasing Cu content at first and reaches a minimum at x = 0.3 and then increases rapidly as Cu content increases further. The variation tendency of magnetization is just opposite. When Cu content gets higher, a semiconductor-like to metal-like crossover in electron transport properties is observed. The martensite resistivity also changes from lower than that of austenite to higher than that. First-principles calculations indicate that these unusual properties are related to the competing occupation of Cu between A and D sites. Cu-doping can also enhance the metallic bonding in Mn2NiGa1−xCux, which can reduce the intrinsic brittleness and improve their mechanical properties. All this provides a fresh idea and method for the development of NiMn-based solid-state refrigeration materials.