Abstract

In situ reduction of bulk, polycrystalline copper(I) aluminate (CuAlO2) results in the formation of an intimate two-phase mixture of metallic Cu and θ-alumina. The microstructure of a partially transformed region was studied at the atomistic scale using high-angle angular-dark-field scanning transmission electron microscopy (HAADF-STEM). The observations were consistent with a topotactic transformation mechanism whereby deintercalation of the Cu atoms occurs sequentially at the edges of the Cu+ atomic layers of the CuAlO2 delafossite structure. The Cu forms faceted nanoislands that exhibit an orientation relationship with the θ-alumina matrix. There is also concomitant outward diffusion of oxygen, and it is suggested that the θ-alumina is formed by the consolidation of the layers of Al–O octahedra of the delafossite structure, with some local rearrangement of the Al3+ ions. This model is supported by the observed continuity of the Al–O layers between the parent CuAlO2 and θ-alumina, together with the orie...

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.