Indeed, solid state atomic diffusio

Indeed, solid state atomic diffusion in metals and ceramics at room temperature is unlikely in most cases because of the relatively large energy barrier for diffusion (usually of the order of a few hundreds of kJ/mol). Diffusion can, however, be activated in the liquid phase or in highly defective interfaces resulting from the reaction between the liquid and the solid. From this point of view, the addition of a liquid phase is expected to change the kinetics of sintering rather than its thermodynamics.