Synchrotron-based high-resolution photoemission spectroscopy study of ZIRLO cladding with H(2)O adsorption: Coverage and temperature dependence

The coverage and temperature dependence of ZIRLO cladding with H(2)O adsorption are studied using synchrotron-based high-resolution photoemission spectroscopy (HRPES). Based on the analytical results of the Zr 3d, O 1 s, C 1 s, and Sn 3d HRPES profiles prior to H(2)O adsorption, we determine the surface compositions of O(2−), hydroxyl OH(−), chemisorbed H(2)O, zirconium carbide, adventitious carbon, Sn metal, and SnO(2) in ZIRLO. When ZIRLO is exposed to H(2)O molecules, the relative proportion of zirconium metal decreases, whereas that of the total zirconium oxides increases, suggesting the reaction between H(2)O and the zirconium metal in ZIRLO. On annealing a sample with 1000 L H(2)O on ZIRLO at 300 °C, Zr(2)O(3) and ZrO(2) decompose, and oxygen diffuses into the bulk, thereby reducing the oxidation states of zirconium on the surface. Moreover, at this temperature, the excess H(2)O molecules on ZIRLO are thoroughly desorbed and tin element is diffused into the bulk in ZIRLO.