The microstructural development of Ag/Ni multilayers during annealing

By use of transmission electron microscopy, including electron-energy-loss spectroscopy with image filtering techniques, and X-ray diffraction, the change in microstructure during annealing of < 111 >-textured Ag/Ni multilayers has been studied. The multilayer break-up proceeds by the formation of Ag and Ni grains which grow at the expense of the multilayer. The driving force originates from the interface energy and large stresses in the multilayers. The grain growth was monitored with time by in-situ X-ray diffraction and an activation energy was derived which suggests that the diffusional mass transport takes place along grain boundaries and interfaces. The < 111 > texture was preserved during the destratification of the multilayer which indicates that the Ag and Ni grains are not formed by a process of nucleation and growth but rather by the growth of individual layers.