foobar

Study of thin films of mixed uranium oxides/nitrides by Photoemission and AES. Films have been prepared by<br> reactive sputter deposition in an Ar plasma in presence of N2 and O2 admixtures. Aim: elucidate if a solid solution<br> of UO and UN (known as uranium oxynitride UNxO1-x) can form by this synthesis method. Such ternary oxide has<br> been described for bulk compounds. Since sputter deposition can produce very finely dispersed systems, this<br> looked like a good method for producing the oxynitride. Oxynitride has uranium in a low oxidation state (UN:<br> formally 3; UO: formally 2). Initially UN films with an increasing oxygen content were deposited. ). The oxynitride is<br> metallic and it can be ashat the U5f are still itinerant and pinned the EF: for UN they are and for UO they<br> also should be. We studied whether the oxygen incorporation goes along with a DOS at EF (pointing to UO<br> formation) or whether it simply leads to the formation of the UO2 semiconductor (no DOS at EF)- Experiment: The<br> series started with deposition of UN and then increasing gradually the O2 pressure. U4f, O1s and VB spectra (by<br> HeII). Also Auger spectra of U, O and N were taken. Depositions were done at room temperature and elevated<br> temperature. We searched for the onset of UO2 formation (characteristic U4f peak), because at sufficiently high O2<br> pressure this oxide will form – oxygen simply displaces nitrogen. File Format: Files are stored in the VAMAS format.<br> This is a universal formed used by commercial data analysis programs such as CasaXPS. Description of the VAMAS<br> format can by found in the internet