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 3 d , O 1 s , C 1 s , and Sn 3 d 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.