Dr. Khachatur V. Manukyan, University of Notre Dame

TITLE: Heterogeneous Combustion and Low Dimensional Materials ABSTRACT:  Two-dimensional (2D) solids (graphene, transition metal dichalcogenides, etc.) have been the subject of intense research over the past decade. The applications of those materials are essentially driven by progress in their production. Currently, there are many methods to prepare 2D materials. However, new synthesis routes still remain a field of immense research activity with focus on inexpensive and scalable methods to produce 2D materials. Heterogeneous combustion processes offer a variety of approaches to prepare nanostructured materials. The self-generated heat of the process creates a localized energy supply, providing some attractive features for synthesis of materials that include extremely high heating rates (up to 106 K∙s-1) of reacting media, high temperatures (up to 3000 K), and short times of reaction completion (on the order of seconds). On the other hand, these characteristics make extremely difficult to control the mechanism of processes and consequently, the microstructures and properties of resultant materials. Recently, a number of important breakthroughs have been made in the field that allowed us to tune the dimensions of combustion products with atomic precision. For example, we have been able to prepare two-dimensional crystals (graphene, molybdenum sulfide, etc.) and quasi-zero dimensional nanostructures (e.g. metals and oxides) with unusual properties. In this presentation, I will give some background on combustion processing and a brief overview on 2D materials. I will then give some examples of specific systems, emphasizing the fundamental relations between combustion conditions, the mechanism of processes and the microstructure of materials at ultralow dimensions. The routes to tune the magnetic and optical properties of materials will also be outlined and discussed.