“Inert” Xenon Reacts with Fluorine
Top, Xenon tetrafluoride forms as colorless crystals. The compound is stable at room temperature, and melts at about 90° C. It doesn’t change during a month’s storage in evacuated nickel or glass containers. The compound is the first to contain xenon and only one other element.
Bottom, Dr. Howard H. Claassen (left) and John G. Malm react five parts of xenon and one of fluorine in a nickel container at 400° C for an hour.
Chemical & Engineering News, October 8, 1962 [pdf]