Composite Cu/VO and VO/Cu Nanofilaments in Cu/Ta2O5/Pt Devices

Evidence for existence of composite copper/oxygen vacancy nanofilaments is presented. The composite conductive nanofilment (CF) is a serial resistive connection of Cu and V o CFs forming a composite V o /Cu CF where the Cu filament segment is formed first and V o filament completes the composite CF. A composite CF has been also formed in reverse order as Cu/V o . Both composite CFs, V o /Cu and Cu/V o , display V form at considerable lower voltages than monolithic CFs.