  Memristive devices made of silicon compatible simple oxides are of great
interest for storage and logic devices in future adaptable electronics and
non-digital computing applications. A series of highly desirable properties
observed in an atomic-layer-deposited hafnia-based stack, triggered our
interest to investigate their suitability for technological implementations. In
this paper, we report our attempts to reproduce the observed behaviour within
the framework of a proposed underlying mechanism. The inability of achieving
the electrical response of the original batch indicates that a key aspect in
those devices has remained undetected. By comparing newly made devices with the
original ones, we gather some clues on the plausible alternative mechanisms
that could give rise to comparable electrical behaviours.
