X-ray studies on the thermal expansion of ruthenium dioxide

A precise X-ray determination of the lattice constants of ruthenium dioxide, RuO₂, has been made in the temperature range 30° to 702°C using a Unicam 19 cm high-temperature powder camera. It has been observed that the c parameter decreases with increasing temperature as in the case of FeF₂ and CrO₂ which also have a ruffle-type structure.