Observation of resistive switching and diode effect in the conductivity of TiTe2 point contacts

TL;DR

This study reports resistive switching and diode effects in TiTe2 point contacts, linked to charge density waves, with potential applications in non-volatile memory and nanotechnology.

Contribution

It is the first to observe resistive switching and diode effects in TiTe2 point contacts, expanding the functional properties of transition-metal dichalcogenides.

Findings

Charge density wave features appear around 150 mV at low temperatures.

Resistive switching occurs above 200 mV, changing resistance by an order of magnitude.

A diode-like effect with hysteresis is observed in soft TiTe2 point contacts.

Abstract

We measured the I(V) and dV/dI(V) characteristics of TiTe2-based point contacts (PCs) from room to helium temperatures. Features indicating the emergence of a charge density wave (CDW) were detected. They represent symmetrical relatively V=0 maxima in dV/dI(V) around 150 mV at liquid helium temperatures, which disappear above 150 K, similar to the case of sister CDW compound TiSe2. Applying higher voltages above 200 mV, we observed resistive switching in TiTe2 PCs from a metallic-like low-resistance state to non-metallic type high-resistance state with a change of resistance by an order of magnitude. A unique diode-like effect was registered in "soft" TiTe2 PCs with hysteretic I(V) at negative voltage on TiTe2. Discovering the resistive switching and diode effect adds TiTe2 to the transition-metal dichalcogenides, which could be useful in developing non-volatile ReRAM and other upcoming nanotechnologies.