The structure and interaction of Mn/ceria interfaces were investigated under ultrahigh vacuum conditions with X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunneling microscopy (STM) techniques. Mn was deposited on well-ordered reducible CeO2(1 1 1) thin films by thermal evaporation at room temperature. Deposition of Mn on both oxidized and reduced ceria surfaces can form the mixed Mn-Ce oxide at the interface. XPS data indicate that Ce4+ is partially reduced to Ce3+, while Mn is formally in the +2 oxidation state. STM results show the formation of two-dimensional manganese oxide features on ceria, which is consistent with the thermodynamics data. Our study demonstrates that Mn can modify both electronic and structural properties of ceria. (c) 2013 Published by Elsevier B.V.