Micro structure and magnetic properties of A1N thin films containing randomly dispersed iron and iron nitride particles

A new type of ferromagnetic film with a two-phase structure was fabricated from Fe-N-Al films deposited by reactive sputtering. The films were investigated by means of X-ray diffraction, electron diffraction and transmission electron microscopy supplemented with energy dispersive spectroscopy. The as-deposited Fe-N-Al films were amorphous, and after annealing they were transformed into AlN films containing randomly dispersed iron and iron nitride particles. The as-deposited films showed small saturation magnetizations (4 π M) as small as 0.4 kG, and after annealing, the films showed a high saturation magnetization 25 times larger than that of as-deposited films. It was also shown that high saturation magnetizations (7.5 ~ 14.1 kG) and high electrical resistivities (ϱ = 4600 ~ 650 μΩ cm) were obtained in annealed AlN thin films containing dispersed iron and iron nitride particles ranging from 36 to 69 at.%Fe in the films.