The properties of metal oxide surfaces are key to their diverse technological applications.
However, the semiconducting nature of metal oxides presents a problem - many surface science techniques are electron based and thus require samples to
be conducting. As such, bulk crystal studies of metal oxides by techniques such as
photoemission spectroscopy (PES) and scanning tunneling microscopy (STM) are
limited to reduced surfaces. Alternatively, thin �films of a metal oxide can be synthesised
on a suitable conducting substrate that mimic the bulk crystal surface whilst
having sufficient conducting character to use these techniques. CeO2 is an important
material found in three-way catalysts that remove pollutants from the exhaust gas of
modern automobiles. Key to this application is the ability of reduced ceria to store
and release oxygen depending on the composition of the exhaust. The addition of
noble metals such as Pd to the ceria surface greatly improves the efficiency of pollutant
conversion evidenced by X-ray photoelectron spectroscopy (XPS) by reducing
the ceria. Resonance photoemission spectroscopy (RESPES) has been used to investigate
the e�ect of Pd on ceria CeO2-x(110) thin �films grown on a Pt(111) substrate.
RESPES is more surface speci�fic than XPS and thus reveals more information on
the surface layers of ceria �films. TiO2(110) is the most studied metal oxide surface,
and has a multitude of applications. Its chemistry with two of the most abundant
chemical species - water (H2O) and oxygen (O2) - is thus very important. H2O has
been shown to dissociate on TiO2 surfaces. TiO2 thin �films grown on W(100) were
used as model system to study the chemistry of the reaction between TiO2 and H2O,
and subsequently the reaction of hydrated surfaces with O2 using XPS. STM was
used to examine the morphology of TiO2(110) �films grown on W(100)-(2 x 1)-O,
changes with fi�lm thickness and methods of improving surface smoothness. The
�first detailed STM images showing row structure of TiO2(110) �films grown on W
are shown