Surface physical property of the CrO_2 thin films prepared using a closed chemical vapor deposition method

摘要

We have examined the intrinsic surface physical property of a CrO_2 thin film by means of surface sensitive photoemission spectroscopy. Epitaxial thin film of CrO_2(100) has been grown on TiO_2(100) by a closed chemical vapor deposition method using a Cr_8O_(21) precursor. Low-energy electron diffraction (LEED) observations find that epitaxial growth of rutile-phase CrO_2 occurs to the top monolayer of the film. Surface sensitive x-ray photoemission spectroscopy (XPS) measurements show a finite intensity in the region of the Fermi energy. The result evidences that the physical nature of near topmost layer of CrO_2 thin film is metallic. Progress of understanding of the surface physical property of CrO_2 thin film helps not only perform a reliable photoemission study to understand the physics of ferromagnetic metal in CrO_2, but also develop the CrO_2-based devices using a half-metallic nature for spintronics applications.