磁性半金属Heusler合金具有高的自旋极化率，如果用于自旋电子器件中，有望大大提高器件的磁电阻性能。本项目将以基于磁性半金属Heusler合金的CPP-SV和MTJ器件作为研究对象，研究材料以及界面对磁电阻性能的影响以及调控机制。在实验上，选取不同的材料，研究成分、结构以及工艺等因素对材料磁性能、输运性能的影响；研究基于不同材料的器件的界面特性以及调控方法；探索通过材料成分的优化、工艺的控制、界面的控制与修饰等手段提高器件的磁电阻性能的方法与途径；在理论上，结合实验结果，研究不同的材料组合的界面的能带结构和磁结构，阐明不同界面影响磁电阻的机制，为更有效提高器件的磁电阻性能提供方法和依据。此外，还将对不同成分、不同超晶格结构的Heusler合金进行研究，弄清成分与结构对磁各向异性的影响及相关机制，探索具有低磁化强度与垂直各向异性的新材料。

CPP-spin valve and magnetic tunnel junction are two kinds of spintroic devices which are very promising for the applications in information storage.Before they can be applied in magnetic memories, the magnetoresistant ratio (MR) and the signal to noise ratio (SNR)of the devices should be improved. Half metallic Heusler alloies which have very high spin polarization are very promising for great enhancement of MR and SNR if being used in the devices. In this project, the focus will be put on the study of related materials and interfaces in Heusler based MR devices (CPP-SVs and MTJs). In the proposed project, both experimental investigation and theoretical study will be performed. Experimentally, we will fabricate MTJ and SV devices based on different materials, and try to improve MR ratio of the devices.by optimizations (composition, structure of Heuslers and fabrication process), selection of spaced layer ,and control of the interface. In theoretical study, we will figure out how composition and chemical order affect the electronic structure and band structure; Find out the band stucuture and magnetc structure at the interface of devices composed of different materials, which may help us clarify the mechanism for interface and materials affecting the MR properties of the device, and explore methods for optimization of interface and materials. Besides,we will also do some research on supperlattice Heusler films, the goal is to understand how composition and structure of the superlattice controls the magnetic anisotropy and to find a proper way to obtain novel Heusler alloys which have low magnetization and perpendicular magnetic anisotropy as well.