FEGDN - A NEW SOFT-MAGNETIC METALLIC THIN-FILM MATERIAL

Thin films of Fe100-x-yGdxNy were sputter deposited in an Ar-N-2 atmosphere in a Balzers triode system. The composition ranges were 4.8 < x < 11 and 11 < y < 25. These films were annealed between 400 and 600 degrees C in a magnetic field to obtain a nano-crystalline structure and to induce a uniaxial anisotropy. After annealing high values for the high-frequency (at 1 MHz) initial relative permeability were obtained: up to mu = 4000. The coercive field of these films was low (around 20 A/m). Fe and GdN phases were identified with X-raj diffraction. The sizes of the Fe and FeGd crystallites are around 10 nm. Both Fe and GdN are ferromagnetic, the latter with a Curie temperature of 69K. Measurement of the saturation magnetization as a function of temperature showed that below 60 K the GdN crystallites are coupled anti-ferromagnetically with the Fe crystallites.