Mott-memories Based on the Narrow Gap Mott Insulators AM4Q8 (A=Ga, Ge ; M = V, Nb, Ta ; Q = S, Se)

ABSTRACTThe narrow gap Mott insulators AM4Q8 (A = Ga, Ge; M= V, Nb, Ta; Q = S, Se) exhibit very interesting electronic properties when pressurized or chemically doped. We have recently discovered that the application of short electrical pulses on these compounds induces a new phenomenon of volatile or nonvolatile resistive switching. The volatile transition appears above threshold electric fields of a few kV/cm, while for higher electric fields, the resistive switching becomes non-volatile. The application of successive very short electric pulses enables to go back and forth between the high and low resistance states. All our results indicate that the resistive switching discovered in the GaM4Q8 compounds does not match with any previously described mechanisms. Conversely, our recent work shows that the volatile resistive switching is related to a purely electronic mechanism which suggests that the AM4Q8 compounds belong to a new class of Mott-memories for which Joule heating, thermochemical or electrochemical effects are not involved. Finally, it is possible to deposit a thin layer of GaV4S8 and to retrieve the reversible resistive switching on a metal-insulator-metal (MIM) device which proves the potential of this new class of Mott-memories for applications.