We have recently combined thin film synthesis, including MBE and laser ablation for growing oxide thin films, and advanced synchrotron spectroscopic techniques, such as spin-polarized soft x-ray absorption, magnetic circular dichroism (MCD), and photoemission, to address current debates and to explore interesting properties of transition metal oxides. In particular, our newly developed quasi-transmission technique is one of the powerful experimental methods in exploring synthetic thin films of magnetic oxides.

In this talk, we will present advanced soft x-ray spectroscopic studies of transition metal oxide thin films. Several interesting case studies will be discussed, including the interesting behaviour of dualistic electronic nature of half-metallic ferromagnet CrO2, and unquenched orbital magnetic moments of magnetite (Fe3O4) above the Verwey transition. In addition, studies of novel electronic properties monolayer NiO and epitaxial EuO thin films with spectacular metal-insulator transition and colossal magneto resistance will also be presented.