Comparison between semiconducting and oxide layers as a reflection layer in spin

2019-07-24 01:12:13

valve spin oxide layers NOL

责任者: Dinia, A. 单位: IPCMS (UMR 7504 du CNRS), ULP-ECPM, 67034 Strasbourg, France 来源出处: Physica Status Solidi (A) Applied Research,2003,198(1):162-168 摘要: It is well established that appropriate oxide capping is effective in forming nano-oxide layers (NOL) in spin-valve films for specular enhancement of giant magnetoresistance (GMR) effect. However, the beneficial effect of a NOL is strongly dependent on its process of formation. Therefore, we are interested to use a nano-semiconducting layer (NSL) for specular reflection instead of oxide layers because its achievement is easier since no specific growth conditions are needed. Moreover, we intend to compare the efficiency of the electronic confinement inside the spin valve induced either by NSL or NOLs for structures with the same stack. We have prepared hard-soft spin valve structures by sputtering on glass substrates with the following stacking sequence: Fe6 nm/Cu3 nm/CoFe1.8 nmRu0.8 nmCoFe3 nmCu2 nm. The reflecting layers have been inserted in the middle of the Fe soft layer and on the top of the spin valve. The GMR effect is enhanced by 60% and 75% respectively for the NSL and the NOL. This shows that the NOL is more efficient in term of electronic confinement. To understand the origin of the difference between the NOL and NSL magnetization measurements as well as transmission electron microscopy are presented. 关键词: Nanostructured materials;Semiconductor materials;Oxides;Reflection;Giant magnetoresistance;Magnetization;Magnetic variables measurement;Transmission electron microscopy;Spin valve films;Nanooxide layers;Nanosemiconducting layer