不同过渡层上Co/Cu/Co三明治结构的巨磁电阻效应研究

通过对不同过渡层上Co(5.5nm)/Cu(3.5nm)/Co(5.5nm)三明治结构的研究，发现过渡层的磁性及过渡层诱导的三明治晶格结构对材料的巨磁电阻效应有重要影响.反铁磁Cr过渡层由于和相邻铁磁Co层之间存在着反铁磁耦合，可以获得6％以上的巨磁电阻值，但它同时使材料的矫顽力较大，因此磁灵敏度不高.Ni和Ti过渡层上Co/Cu/Co三明治结构，由于形成了强的（111）织构，其巨磁电阻值也达到5％以上.磁性材料Ni过度层还使三明治结构材料的矫顽力大为下降，从而显著提高了材料的磁灵敏度. 关键词：

Study on Giant Magnetoresistance of Co/Cu/Co Sandwich on Different Buffer Layers

The influence of the different buffer layers on the giant magnetoresistance (GMR) of the Co/Cu/Co sandwich was investigated. It was found that the GMR effect strongly depends on the magnetism of the buffer layer and crystallization of the sandwich induced by the buffer layer. Due to the anti-ferromagnetic coupling between the Cr and Co layer, anti-ferromagnetic Cr layer enlarged the difference of the magnetic behavior between the two Co layers and presented a high GMR value larger than 6%. However, as the coercive force was enlarged also, its magnetic sensitivity could not be high. Ti and Ni buffer layer could form strong (111) texture in the sandwich, which also enlarged the difference between the two Co layers, and achieved GMR values over 5%. Furthermore, the ferromagnetic Ni layer reduced the coercive of the sandwich, and enhanced the sensitivity significantly.