Defect and Diffusion Forum (DDF) (formerly Part A of ''Diffusion and Defect Data'') is designed to publish up-to-date scientific research and applied aspects in the area of formation and dissemination of defects in solid materials, including the phenomena of diffusion.

In addition to the traditional topic of mass diffusion, the journal is open to papers from the area of heat transfer in solids, liquids and gases, materials and substances.