Thin films preparation by rf-sputtering of copper/iron ceramic targets withudCu/Fe=1: From nanocomposites to delafossite compounds

摘要

In the Cu–Fe–O phase diagram, delafossite CuFeO2 is obtained for the CuI oxidation state and for the Cu/Fe=1 ratio. By decreasing theudoxygen content, copper/spinel oxide composite can be obtained because of the reduction and the disproponation of cuprous ions. Many physicaludproperties as for instance, electrical, optical, catalytic properties can then be affected by the control of the oxygen stoichiometry.udIn rf-sputtering technique, the bombardment energies on the substrate can be controlled by the deposition conditions leading to differentudoxygen stoichiometry in the growing layers.udBy this technique, thin films have been prepared from two ceramic targets: CuFeO2 and CuO+CuFe2O4. We thus synthesized either Cu0/udCuxFe1−xO4 nanocomposites thin films with various Cu0 quantities or CuFeO2-based thin films.udTwo-probes conductivity measurements were permitted to comparatively evaluate the Cu0 content, while optical microscopy evidenced a selfassemblyudphenomenon during thermal annealing.