Simulations and Experiments on the Synthesis of 2D Nanomaterials by Resistive Heating of Metallic Wires

Two dimensional materials are synthesized from different techniques like <i>chemical vapor deposition</i> or <i>physical vapor deposition</i> among others. Thermal oxidation growth has the advantage of its simplicity, but most of the reported synthesis of oxide low dimensional structures by this method, required growth times in the range of hours. A more rapid method of metal oxide structures synthesis, also based on thermal oxidation of metals, is the direct resistive heating of a metallic wires by the flow of an electric current in ambient conditions. The high current density applied during the Joule heating favors the diffusion processes involved in the growth, been considered the underlying mechanism the electromigration processes. Applying external electric fields with different orientations to the current flow during treatments, we are able to inhibit or enhance the ions diffusion and, therefore, the formation of structures.<br/>In this work, we report a simple and effective method to obtain nano- and microstructures in a very fast way with promising applications. Simultaneous COMSOL simulations have been carried out to verify the experimental result. A detailed analysis of the behavior of the current density, potential difference and thermal gradient is presented in order to understand what is happening in the material during the flow of the electric current and how the growth originates on the surface of the wire. Simulations have also been carried out for treatments with electric field application with the purpose of comprehend how the electric field interacts with the material during Joule heating. In summary, the results obtained shed some light to better understand how electromigration processes take part in the formation of the structures. This study encourages in-situ measurements during the growth process by direct resistive heating of a metallic wire, which could also be extrapolated to a wide range of materials.