  Neuromorphic computing aims to mimic the architecture and the information
processing mechanisms of the mammalian brain, appearing as the only avenue that
offers significant energy savings compared to the standard digital computers.
Memcapacitive devices (which can change their capacitance between different
non-volatile states upon the application of electrical stimulation) can
significantly reduce the energy consumption of bioinspired circuitry. In the
present work, we study the multimem (memristive and memcapacitive) behavior of
devices based on thin films of the topotactic redox
La$_{1/2}$Sr$_{1/2}$Mn$_{1/2}$Co$_{1/2}$O$_{3-x}$ (LSMCO) perovskite modified
with Sm:Ce$O_2$ (SCO), grown on Nb:SrTiO$_{3}$ with (001) and (110) out of
plane orientations. Either the self assembling at the nanoscale of both LSMCO
and SCO phases or the doping with Ce(Sm) of the LSMCO perovskite were observed
for different fabrication conditions and out of plane orientations. The impact
of these changes on the device electrical behavior was determined. The optimum
devices resulted those with (110) orientation and Ce(Sm) doping the perovskite.
These devices displayed a multimem behavior with robust memcapacitance and
significantly lower operation voltages (especially the RESET voltage) in
comparison with devices based on pristine LSMCO. In addition, they were able to
endure electrical cycling (and the concomitant perovskite topotactic redox
transition between oxidized and reduced phases) without suffering
nanostructural or chemical changes. We link these properties to an enhanced
perovskite reducibility upon Ce(Sm) doping. Our work contributes to increase
the reliability of LSMCO based multimem systems and to reduce their operating
voltages closer to the 1 V threshold, which are key issues for the development
of nanodevices for neuromorphic or in memory computing.
