Lawrence Berkeley National Laboratory

Intermetallic phases are preferred to reduce the amount of platinum used for catalytic applications as compared to solid solution alloys, due to their stability at elevated temperatures while preserving or even enhancing the catalytic properties. Here, we show a two-step process to form an intermetallic NiPt L10 phase. In this work, NiPt solid solution thin films were fabricated by direct current and high-power impulse magnetron sputtering processes, which allow for precise thickness and chemical composition control. Following deposition, an additional annealing step is used to form the desired intermetallic phase. We show that the required annealing time for intermetallic phase formation is considerably reduced for NiPt thin films with a thickness of 240 nm, as compared to its bulk counterpart.