Scaleable stagnation-flow reactors for uniform materials deposition: Application to combustion synthesis of diamond

We describe two inherently scaleable geometries for chemical-vapor-deposition and heat-transfer processes that are based on stagnation flows. The ‘‘coflow’’ and ‘‘trumpet-bell’’ designs result in radially uniform fluxes to surfaces and they optimize the use of reagents. Using a trumpet-bell burner, we have grown uniform films of diamond from a substrate-stabilized flat flame of C2H2/H2/O2.