  Tuning is an essential requirement for the search of dark matter axions
employing haloscopes since its mass is not known yet to the scientific
community. At the present day, most haloscope tuning systems are based on
mechanical devices which can lead to failures due to the complexity of the
environment in which they are used. However, the electronic tuning making use
of ferroelectric materials can provide a path that is less vulnerable to
mechanical failures and thus complements and expands current tuning systems. In
this work, we present and design a novel concept for using the ferroelectric
Potassium Tantalate ($KTaO_3$ or KTO) material as a tuning element in
haloscopes based on coupled microwave cavities. In this line, the structures
used in the Relic Axion Detector Exploratory Setup (RADES) group are based on
several cavities that are connected by metallic irises, which act as
interresonator coupling elements. In this article, we also show how to use
these $KTaO_3$ films as interresonator couplings between cavities, instead of
inductive or capacitive metallic windows used in the past. These two concepts
represent a crucial upgrade over the current systems employed in the dark
matter axions community, achieving a tuning range of $2.23 \, \%$ which
represents a major improvement as compared to previous works ($<0.1 \, \%$) for
the same class of tuning systems. The theoretical and simulated results shown
in this work demonstrate the interest of the novel concepts proposed for the
incorporation of this kind of ferroelectric media in multicavity resonant
haloscopes in the search for dark matter axions.
