铁磁形状记忆合金具有大磁致应变效应，在驱动器和传感器中有重要应用前景。马氏体相晶格畸变度a/c是决定其本征磁致应变的关键因素。目前在5M和7M马氏体单晶中已通过实验获得了与其本征磁致应变相当的性能并证明了其与a/c的关联性，然而如何进一步提高铁磁形状记忆合金的磁致应变值具有挑战性。申请者近期发现，在快速凝固NiMnGa合金中稀土元素部分固溶，诱导马氏体晶格畸变度显著增大，这样有望显著提升本征磁致应变值；同时，部分稀土形成纳米第二相，抑制马氏体相变，在合金中形成纳米马氏体结构，有望引发全新物理效应。因此，本项目以稀土元素掺杂NiMnGa快速凝固甩带合金为研究对象，研究稀土元素的存在形式对于合金微观结构的影响规律，揭示其对于合金内禀磁性和马氏体相变行为的作用机制，探索甩带合金大磁致应变等物理效应，期望为新性能铁磁形状记忆合金发展提供理论依据。

Ferromagnetic shape memory alloys is an important materials with potential application in actuators and sensors for the possession of large magnetostrain effect. The lattice distortion degree a/c of martensite phase is the key facter of intrinsic magnetostrain property. Currently, the ways adjusting the intrinsic magnetostrain are mainly focused on the transforming of the martensite type. Recently, we discovered that doping rare earth atoms in rapid solidified NiMnGa alloys can induce the partial solid solution of rare earth atoms and others forms nanoprecipitates. This result produces the strong distortion of martensite lattice, and suppresses the martensitic transformation, and puts forward to the formation of nano-martensite. In this way, larger intrinsic magnetostrain property and new physical effects are expected. Therefore, in this item, rare earth elements with different anisotropies are chosen to be added into NiMnGa allos and the melt spinning ribbons are produced. The influences on martensite crystal structure, lattice parameters and magnetocrystalline anisotropies by rare earth atoms addition are studied, the mechanism the martensitic transformation suppressed effect are revealed. The relationship between the microstructures and the magnetic, electrical, mechanical properties are investigated. This item may provide theoretical foundation for the development of ferromagnetic shape memory alloys.