Stierle A, Kasper N, Dosch H, Lundgren E, Gustafson J, Mikkelsen A, Andersen J N
Max-Planck Institut für Metallforschung, Heisenbergstrasse 3, D-70569 Stuttgart, Germany.
J Chem Phys. 2005 Jan 22;122(4):44706. doi: 10.1063/1.1834491.
The oxidation of Pd(100) and the formation of PdO was studied in situ using surface x-ray diffraction. A bulklike, epitaxial PdO film is formed at oxygen partial pressures beyond 1 mbar and sample temperatures exceeding 650 K. The main orientation is PdO(001)/Pd(001), based upon bulk reflections from the PdO film. By comparing with measurements from the Pd crystal truncation rods, we estimate an rms surface roughness of 6 A, in good agreement with previous high pressure scanning tunneling microscopy measurements. Finally, we observed the transformation from the (radical5 x radical5) surface oxide to PdO bulk oxide at 675 K and 50 mbar O(2) pressure.
利用表面X射线衍射原位研究了Pd(100)的氧化及PdO的形成。在氧分压超过1毫巴且样品温度超过650 K时，会形成块状外延PdO薄膜。基于PdO薄膜的体反射，主要取向为PdO(001)/Pd(001)。通过与Pd晶体截断棒的测量结果进行比较，我们估计均方根表面粗糙度为6埃，这与之前的高压扫描隧道显微镜测量结果吻合良好。最后，我们观察到在675 K和50毫巴O₂压力下，(√5×√5)表面氧化物向PdO体氧化物的转变。
