Influence of a passivation layer on strain relaxation and lattice disorder in thin nano-crystalline Pt films during in-situ annealing

In this work we compared the relaxation of strain and lattice disorder in thin nano-crystalline Pt films for samples covered with a Si3N4 layer and samples without a cover layer, respectively.We measured thickness and interplanar distance of the Pt film by X-ray reflectometry and X-ray diffractometry during insitu annealing using synchrotron radiation. The results show that strain and lattice disorder relaxation are impeded if the Pt film is sealed with a cover layer to suppress the creation of vacancies at the Pt surface. This emphasizes the postulated important role of the generation of vacancies at the free surface of thin metal films for strain relaxation during isothermal annealing.