Control of Microstructure in Iron–Carbon Thin Films by Means of Electromigration

Herein, it is demonstrated that high DC electric current densities can be used to tailor the microstructure of iron–carbon thin films. Specifically, elongated ferrite grains can be formed in a nanocrystalline matrix via a process involving electromigration‐induced carbide migration. Herein this article, the parameters that are required to produce and control elongated grain formation in the Fe(C) system are mapped out and they are interpreted in terms of carbon electromigration, and the flux divergences need to reach a critical carbon concentration for precipitate growth and migration. Possible approaches to allow more precise control of the elongated grains are discussed, as are the requirements for material systems where microstructure control through electromigration should be feasible.