High moment soft magnetic FeTiN thin films for recording head materials

Soft magnetic properties and thermal stability of Fe-Ti-N alloys films have been investigated. Thin films with composition in the range of 8-10 at. % Ti, 10.5-14 at. % N, and balance Fe were prepared by reactive sputtering method. The films exhibit good soft magnetic properties in the as-deposited condition without any post heat treatment, e. g., low coercivity H-c similar to 1.5 Oe, high permeability mu similar to 3200 at 1 MHz and very high saturation magnetization 4 pi M-s similar to 24 kG. The thermal stability of these films was also found to be good, e. g., H-c was less than 2 Oe, and 4 pi M-s was higher than 23 kG for the films annealed up to 500 degrees C. The high electrical resistivity rho similar to 100 mu Ohm cm of the films can minimize the eddy current loss in the high frequency applications. The combination of high 4 pi M-s and relatively high anisotropy field H-a similar to 10 Oe in the film is conductive to the suppression of the undesirable ferromagnetic resonance interfere up to the GHz frequency range. (C) 1999 American Institute of Physics. [S0021-8979(99)04506-5].