A superconducting Ba2DyCu3O6.5 (orthorhombic II phase) thin film is formed on a MgO(100) substrate at 420°C by molecular beam epitaxial growth using NO2 as an oxidant. Metal elements Ba, Dy, and Cu are sequentially supplied from K cells onto MgO(100) at 420°C under a flow of 5×10-5 Pa of NO2. The film gradually cooled in situ under the identical pressure of NO2 shows metallic behavior in the normal state and a Tczero of 50 K. The lattice constant of the c axis is observed at 11.75 Å, which is known as an orthorhombic II phase of bulk Ba2DyCu3O 6.5. Due to the slow deposition rate, the film thus formed is oriented with the c axis perpendicular to the surface in spite of the low-temperature growth condition.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)