o/ZnO薄膜的结构、磁性和磁电阻效应

o/ZnO films were deposited on glass substrates by magnetron sputtering, and then were annealed in vacuum. And the influence of Co layer thickness, period number and post-annealing on the structures and magnetoresistance (MR) of the films was investigated. The results show that the room temperature MR of the as-deposited Co/ZnO films is initially increased, and then decreased with the increase of Co layer thickness from 0.3 nm to 1 nm. And the as-deposited [Co(0.6 nm)/ZnO(0.4 nm)]60 film shows the maximum negative MR value of 10.4%. The influence of the period number on the films with the fixed total thickness is investigated, which illuminates that the films with large period number and thin Co layer and ZnO layer in a period exhibit large MR values. Post-annealing process leads to the remarkable enhancement of both the coercivity and saturation magnetization, and the rapid reduction of both resistances and MR ratios of the films. The magnetoresistance of the films may be related with the spin related tunnelling taking place between isolated Co grains by ZnO.