Structural Study of Iron Oxide Thin Films Using Pre-edge Feature of XANES

摘要

Recently there has been a very high demand for small scale magnetic storage devices. The industry sector has consistently demanded sub micron or even nano-meter scale magnets. Magnetic thin films often contain several layers of coating. For the purpose of this study, we prepared thin film magnets by spin coating a precursor containing iron into a glass substrate. The thickness of the films was controlled by the spin rate. Precursor films on the substrate were then annealed to 600°C for 3 hours in air. The micro structure of iron in the films was investigated using the pre-edge feature that appears in the X-ray Absorption Near Edge Structure (XANES) for samples containing different iron layers. The main absorption edge peak position and pre-edge energy position were identical in all of the samples. This indicates that there was no change in the charge state of the iron regardless of the number of layers. However the intensity of the pre-edge feature decreases as number of layers increases which shows a decrease of Fe-O compounds as the number of layers increases.