Effects of hydrogen treatment and substrate hardness on the negative magnetostrictive thin films and their coatings

摘要

Negative magnetostrictive Sm-Fe films and Pd films were prepared by a DC magnetron sputtering process on singlecrystalSi (100) substrates and on polyimide substrate. Controlled amount of hydrogen was loaded electrochemically viastep-by-step method to the prepared films. The interferometric microscope and Newton ring method were applied to scanthe curvature and 3D geometry of the films in equilibrium states at each hydrogen concentration. Developments of thecompressive stress by a small amount of hydrogen uptake, and the stress release via film delamination at high hydrogenconcentration regime were observed. The validity of the hydrogen loading treatment for tuning internal stress in Sm-Fefilm, its adhesion, and the in-plane stress impact on the thermodynamic properties in capping metal-hydrogen systemswill be discussed.