The martensitic transformation, kinetics, elastic and magnetic properties of the Ni_2-xMn_1.5In_0.5Co_x (x = 0-0.33) ferromagnetic shape memory alloys were investigated experimentally and theoretically by first-principles calculations. First-principles calculations show that Co directly occupies the site of Ni sublattice, and Co atoms prefer to distribute evenly in the structure. The optimized lattice constants are consistent with the experimental results. The martensitic transformation paths are as follows: PA ↔ FA ↔ 6 M^FIM ↔ NM^FIM when 0 ≤ x < 0.25; PA ↔ FA ↔ 6 M^FM ↔ NM^FIM with 0.25 ≤ x < 0.3 and PA ↔ FA ↔ NM^FM with 0.3 ≤ x ≤ 0.33 for Ni_2-xMn_1.5In_0.5Co_x (x = 0-0.33) alloys. The fundamental reasons for the decrease of T_M with increasing Co content are explained from the aspects of first-principles calculations and martensitic transformation kinetics. The component interval of the magnetostructural coupling is determined as 0 ≤ x ≤ 0.25 by first-principles calculations. Furthermore, the origin of the demagnetization effect during martensitic transformation is attributed to the shortening of the nearest neighboring distances for Ni-Ni (Co) and Mn-Mn. Combining the theoretical calculations with experimental results, it is verified that the T_M of the Co6 alloy is near room temperature and its magnetization difference ΔM is 94.6 emu/g. Therefore, magnetic materials with high performance can be obtained, which may be useful for new magnetic applications.

 通过第一性原理实验和理论研究了Ni _{2- x} Mn _1.5 In _0.5 Co _x（x = 0-0.33）铁磁形状记忆合金的马氏体相变，动力学，弹性和磁性。第一性原理计算表明，Co直接占据Ni亚晶格的位置，Co原子更喜欢在结构中均匀分布。优化的晶格常数与实验结果一致。马氏体转变路径如下：PA↔FA↔-6 M ^FIM ↔NM ^FIM当0≤ X <0.25; PA↔FA↔6M的^FM ↔NM ^FIM用0.25≤ X <0.3和PA↔FA↔NM ^FM用0.3≤ X ≤0.33的Ni _{2- X}的Mn _1.5在_0.5钴_X（X  = 0-0.33）合金。对于减少的根本原因ŧ_中号与钴含量的增加从第一原理计算和马氏体相变动力学方面的解释。磁结构耦合的分量间隔确定为 0≤x 根据第一性原理计算，≤0.25。此外，马氏体相变期间的退磁作用的起因归因于Ni-Ni（Co）和Mn-Mn的最近邻近距离的缩短。结合理论计算和实验结果，证明了Co6合金的T _M接近室温，磁化强度差ΔM为94.6 emu / g。因此，可以获得高性能的磁性材料，其对于新的磁性应用可能是有用的。