  Over the past few years, ionic conductors have gained a lot of attention
given the possibility to implement them in various applications such as
supercapacitors, batteries or fuel cells as well as for resistive memories.
Especially, layered two-dimensional (2D) crystals such as h-BN, graphene oxide
and MoSe2 have shown to provide unique properties originating from the specific
2D confinement of moving ions. Two important parameters are the ion
conductivity and the chemical stability over a wide range of operating
conditions. In this vein, Rb2Ti2O5 has been recently found displaying
remarkable properties such as superionic conduction and colossal equivalent
dielectric constant. Here, a first approach to the study of the electrical
properties of layered Rb2Ti2O5 at the 100-nanometer scale is presented.
Characterizations by means of micro-Raman spectroscopy and atomic force
microscope (AFM) measurements of mechanically exfoliated RTO nanocrystals via
the so-called adhesive-tape technique are reported. Finally, the results of
electrical measurements performed on an exfoliated RTO nanocrystals are
presented, and are found to be consistent with the results obtained on
macroscopic crystals. 4
