Electromechanical behavior of pulsed laser deposited platinum-based metallic glass thin films

Noble-metal-based amorphous alloys show exceptional electrocatalytic activity and durability, and are promising for next generation electrochemical devices for energy conversion and storage. Here, we report on the electro-mechanical behavior of pulsed laser deposited Pt-based metallic glass thin film of composition Pt57.5Cu14.7Ni5.3P22.5. Pulsed laser deposition is ideally suited for the synthesis of thin films with complex compositions since the congruent evaporation process ensures that the composition of the ablation target is replicated in the film being grown. High resolution transmission electron microscopy and X-ray diffraction show that the deposited film is fully amorphous. X-ray photoelectron spectroscopy shows that the constituent elements in the thin film are in their elemental state, forming an isotropic amorphous structure. Nano-indentation determined elastic modulus and hardness values of 52.8 and 2.98GPa, respectively. In addition, the thin-films exhibited unusually high ductility and low coefficient of friction. The sheet resistance of the as-deposited films was found to be around 76msq(-1). By current measurement during indentation, we demonstrate current drop during shear band nucleation, which is attributed to increased electron scattering from localized heating.