Increased magnetic moment induced by lattice expansion from α-Fe to α-Fe8N

Here we provide experimental evidence by the careful preparation of thin films with controlled nitrogen content and induced tetragonality as a consequence. We have correlated the increase of the unit cell volume in expanded bcc Fe buffer-free and epitaxial thin films with their accurately measured magnetic moment, in-plane saturation field, magnetic domain patterns and change in electronic structure by systematically changing the amount of added nitrogen, allowing a comparison to the theoretical predictions.