Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

In this study we investigated the correlation between microstructure and residual strain relaxation innanocrystalline Pt films with a thickness of about 20 nm produced by different deposition techniques:magnetron sputtering and ion beam sputtering. X-ray diffractometry was carried out using synchrotronradiation. The out-of-plane interplanar distance was measured during isothermal in situ annealing attemperatures between 130◦C und 210◦C. The thermoelastic expansion coefficient is equal for both types of nanocrystalline Pt films and slightly lower than for coarse grained Pt. The relaxation of residual out-of-plain strain depends on temperature and is significantly stronger in the case of the magnetron sputteredfilms than for the ion beam sputtered films. Different relaxation of compressive stress is ascribed tothe different microstructures which evolve during deposition via the corresponding deposition tech-nique. Thickness fringes around the (1 1 1) Bragg peak deposited via magnetron sputtering reveal thatthese films are essentially composed of columnar (1 1 1) oriented grains which cover the whole filmthickness. In contrast, no thickness fringes are observed around the (1 1 1) Bragg peak of films preparedby ion beam sputtering indicating a significantly different microstructure. This is confirmed by ElectronBackscatter Diffraction which reveals a (1 1 1) texture for both types of films. The (1 1 1) texture, however,is significantly stronger in the case of the magnetron sputtered films. Grain growth at low homologoustemperatures is considered to be an important contribution to relaxation of residual stress.