Author/Authors :
Zhang، نويسنده , , H.J. and Lu، نويسنده , , B. and Lu، نويسنده , , Y.H. and Xu، نويسنده , , Y.F. and Li، نويسنده , , H.Y. and Bao، نويسنده , , S.N. and He، نويسنده , , P.، نويسنده ,
Abstract :
Investigations of growth of RuO2 thin layer on Ru ( 1 0 1 ¯ 0 ) by oxidation were performed by means of scanning tunneling microscopy (STM). The results showed that the morphologies and the structures of RuO2 thin film grown on Ru ( 1 0 1 ¯ 0 ) depend crucially on the O2 pressure and reaction temperature. At a sample temperature of about 600 K and an O2 pressure of 5 × 10−6 mbar, the oxidation of Ru ( 1 0 1 ¯ 0 ) leads to formation of Ru–O chain structures, which can be attributed to the dynamical hindrance arisen from the repulsive dipolar interaction. This dynamical hindrance can be overcome, and the RuO2(1 0 0)-(1 × 1) phase, together with the RuO2(1 0 0)-c(2 × 2) patch, can be formed by increasing O2 pressure. Further increasing the sample temperature up to 760 K at the same O2 pressure, the oxidation results in formation of a RuO2(1 1 1) film over the RuO2(1 0 0) thin layer.
