Resistive Switching in Mott Materials.

Mott materials are a class of correlated materials which undergo resistive switching by creating a metallic filament between electrodes under the presence of an electric field. Such resistive switching has potential application in resistive random access memories and artificial neuron. For its use in electronic devices, it is necessary to characterize the switching time and energy necessary for the transition which have not been almost studied yet. Additionally, it is also crucial to understand about the geometry, conductivity, chemical composition of filaments on a nanoscale. So in the first part of the work, we experimentally determined the switching energy for the resistive switching in GaMo4S8 narrow gap Mott materials at 250 K, which fluctuates depending on the electric field between 313 μJ and 112 μJ. Furthermore, a simple model is put out to estimate the characteristic transition energy per volume, which is 25 pJ/ μm3. The final part of the work is dedicated to the characterization and understanding of a permanent filament created by a small electric field pulse for small, micrometric interelectrode distances. The filament was found to be conductive and trench shaped by the C-AFM characterization. Further examination using EDX and Raman characterization revealed that the filament has gone through a chemical change thus corresponding to a specific irreversible resistive transition rather than a non-volatile Mott transition.