Structure and solid state reactions of laser-deposited and sputtered Fe/Nb and Fe/Ag multilayers

The structure of laser-deposited and sputtered Fe/Nb and Fe/Ag multilayers was investigated by x-ray diffraction. Significant differences in the textures, sharpness of the interfaces, and critical bilayer thicknesses for alloys are obtained for these two deposition processes. For small bilayer thicknesses, the measured x-ray-diffraction patterns were analyzed by computer simulations using a one-dimensional model, which includes the occurrence of amorphous or disordered interlayers between the crystalline layers and takes layer thickness fluctuations into account. These simulations indicate that already in as-prepared Fe/Nb multilayers thin amorphous interlayers exist and describe the thickness increase during an interdiffusion reaction already in the early stages of the transformation. In the case of Fe/Ag multilayers, the interfaces are disordered after deposition and first sharpen during annealing at about 250 °C, before grain coarsening occurs.