A cobalt ultrathin film, which shows a large change in Curie temperature by an electric field application, has been studied by X-ray reflectometry with applying electric fields. The cobalt film was made by the sputtering method on top of a Pt buffer layer, and capped with a MgO layer. X-ray reflectometry shows that the change in Co thickness caused by the applied voltage up to ±10 V was less than 0.06 Å. The reflectivity signal intensity shows a characteristic kink at the Co K-absorption edge. The spectrum does not show any change with applying voltage. As a result, electric field effects on the structure and chemical states of Co in the Co ultrathin film were found to be minor.
- Thin Film
- X-ray Reflectivity
ASJC Scopus subject areas
- Physical and Theoretical Chemistry