In this work we investigate the strain state in Ni films belonging to [Ni(t_Ni)/Cu(t_Cu)] $\times$ N superlattices (with t_Ni = 2 nm, 3 nm, t_Cu from 0 to 3 nm and N between 1 and 6) by Extended X-ray Absorption Fine Structure at the Ni K-edge. The strain of these Ni blocks can be up to 80% larger than that obtained for single thin films with the same content of Ni. The dependence of the strain on N indicates that its relaxation is not progressive with N but gets blocked for certain N values. Also, the replacement of a single Ni layer by Cu, at the middle of the Ni block, results in a significant increment of the strain of the nickel layers, which manifests the relevant effect of the introduction of copper. The large strain values observed suggest the presence of blocking mechanisms acting on the propagation of dislocations. We argue that this observation is related to repulsive interactions between dislocations enhanced by nonhomogeneos stress due to presence of the copper layers separating the Ni blocks.

在这项工作中，我们研究了属于[Ni（t _Ni）/ Cu（t _Cu）]的Ni膜的应变状态。$\times$通过在Ni K边缘的扩展X射线吸收精细结构，可制出N个超晶格（t _Ni = 2 nm，3 nm，t _Cu从0到3 nm，N在1-6之间）。这些镍块的应变可以比具有相同镍含量的单个薄膜获得的应变大80％。上的应变的依赖性Ñ指示其松弛不是渐进与Ñ但是被阻断某些Ñ价值观。而且，在Ni块的中间用Cu代替单个Ni层导致镍层的应变的显着增加，这表明引入铜的相关效果。观察到的大应变值表明存在作用于位错传播的阻断机制。我们认为，该观察结果与位错之间的排斥性相互作用有关，该位错之间的相互作用是由非均相应力引起的，该非均质应力是由于分隔镍块的铜层的存在而引起的。