哈斯勒合金Ni-Co-Mn-Sn的马氏体相变及其磁热效应研究

通过结构和磁性测量，研究了四元哈斯勒合金Ni_50-xCo_xMn₃₈Sn₁₂（x=1, 2, 4, 6, 8）的晶体结构和相变特征.结果表明，Co原子的掺杂不但没有影响三元哈斯勒合金Ni-Mn-Sn的原有结构，而且还增强了样品在奥氏体相的铁磁交换作用.此外，通过Maxwell方程计算了其中三种成分样品（x= 2, 4, 6）的磁熵变ΔS_{M关键词： 哈斯勒合金 Ni-Co-Mn-Sn 马氏体相变 磁热效应}

Martensitic transformation and magnetocaloric effect in Ni-Co-Mn-Sn Heusler alloy

The crystal structure and phase transition in Ni_(50-x) Co_x Mn_(38)Sn_(12) (x =1, 2, 4, 6, 8) Heusle alloys were investigated by means of structure analysis and magnetism measurements. The results show that the doping of the Co atom affects neither the original structure of Ni-Mn-Sn Heusler alloys, nor the ferromagnetic interaction strengthens in the austenitic state. Furthermore, based on Maxwell equation, the magnetic entropy change (△S_M) of three samples (x = 2, 4, 6) has been calculated. A large magnetic entropy change of 37.09 J/kg K at about 320 K for a magnetic field change of 50 kOe is obtained in Ni_(48)Co_2Mn_(38)Sn_(12) alloy.