In situ electron microscopy investigations of solid-state synthesis in Al/Au thin bilayer films

In situ transmission electron microscopy investigations of solid-state synthesis in Al/Au thin bilayer films are conducted. The samples are heated in the column of a transmission electron microscope. The heating temperature is changed from room temperature to 300°C with a heating rate of up to 120°C min^?1. It is found that solid-phase synthesis starts at ≈100°C. At 140 ± 5°C, two crystal phases, Al₂Au (Fm3m) and AlAu₂ (I4/mmm), are simultaneously observed, while at 235 ± 5°C and higher (up to 300°C) only Al₂Au phase is detected.