  TiSe2 has received much attention among the transition metals chalcogenides
because of its thrilling physical properties concerning atypical resistivity
behavior, emerging of charge density wave (CDW) state, induced
superconductivity etc. Here, we report discovery of new feature of TiSe2,
namely, observation of resistive switching in voltage biased point contacts
(PCs) based on TiSe2 and its derivatives doped by S and Cu (TiSeS, CuxTiSe2).
The switching is taking place between a low resistive mainly metallic-type
state and a high resistive semiconducting-type state by applying bias voltage
(usually below 0.5V), while reverse switching takes place by applying voltage
of opposite polarity (usually below 0.5V). The difference in resistance between
these two states can reach up to two orders of magnitude at the room
temperature. The origin of the effect can be attributed to the variation of
stoichiometry in PC core due to drift/displacement of Se/Ti vacancies under
high electric field. Additionally, we demonstrated, that heating takes place in
PC core, which can facilitate the electric field induced effect. At the same
time, we did not found any evidence for CDW spectral features in our PC spectra
for TiSe2. The observed resistive switching allows to propose TiSe2 and their
derivatives as the promising materials, e.g., for non-volatile resistive random
access memory (ReRAM) engineering.
