Effect of thickness on structural and magnetic properties in nanocrystalline Fe-N thin films

► We explain the thickness dependent structural and magnetic properties of Fe-N films. ► We observe a structural transformation from ε-Fe3N to γ-Fe4N phase with thickness. ► The influence of structural properties on magnetization and coercivity is explained. ► The effect of strain and size of Fe-N grains on domain wall motion is discussed.