Investigation of structure and magnetic properties of the as-deposited and post-annealed iron nitride films by reactive facing-target sputtering

摘要

Structure and magnetic properties of the as-deposited and post-annealed iron nitride films have been investigated systematically. A series of phases containing a-Fe, ε-Fe_3N, £-Fe_2N and y"-FeN were obtained as nitrogen flow rate (Fn2 ) increases from 0.5 to 30 seem. An increase of the nitrogen concentration in the as-deposited films could be concluded from the phase transition with the increasing F_N2. After being annealed, some of the iron nitride phases are decomposed and y'-Fe_4N appears in the films. The magnetic characteristics are dependent on Fn_2 . which can be ascribed to the facts that the nitrogen in the films turns the valence states of Fe into Fe+ or Fe~dipole with high magnetic momentum or ever H-like bond p_e+/dipole with low magpie momentum based on the bond-band-barrier correlation mechanism.