A New method of measuring ruthenium activity in ruthenium-containing alloys by using thermogravimetric analysis

Liu, J.  ; Nakajima, Kunihisa  ; Miwa, Shuhei  ; Shirasu, Noriko  ; Osaka, Masahiko  

A new method named TG calibration curve method has been proposed to evaluate the Ru activity in the Ru-containing alloys by using the kinetic relationship between oxidative evaporation rate of Ru atom and overall vapor pressures of various RuOx gases in the experimental system constructed by the authors. The experimental results show that the oxidative evaporation rate of Ru atom from experimental powders is approximately proportional to the overall vapor pressures over powders. By using their specific quantitative relationship, we determined the Ru activity in RuPd alloy in the temperature range from 1523 to 1673 K. The obtained values of Ru activity agree well with those theoretically calculation, and indicated the reliability of this new method.