Soft magnetic properties of as-deposited Fe-Hf-C-N and Fe-Hf-N nanocrystalline thin films

Abstract

As-deposited Fe-Hf-C-N nanocrystalline thin films are investigated to improve soft magnetic properties by controlling both the compositions of the films and sputtering conditions, such as input power and N-2 partial pressure. As-deposited Fe-Hf-N thin films are also investigated fur the applications to simplify the fabrication of magnetic devices. The as-deposited Fe-Hf-C-N and the as-deposited Fe-Hf-N thin films are fully nanocrystallized during deposition by controlling the composition and sputtering condition. The thin films show the excellent soft magnetic properties of saturation magnetization similar to 17.5 kG/similar to 16.5 kG and coercivity similar to 0.5 Oe/similar to 0.5 Oe when the compositions of each film are 6.8-7.2 at % Hf, 2.0-2.5 at % C, 9.8-10.8 at % N, and balanced Fe/6.3-7.0 at % Hf, 13.2-14.0 at % N, and balanced Fe, respectively. Both of the thin films exhibit an outstanding frequency dependence of permeabilities, i.e., the effective premeabilities of the films remain flat over 3000 up to 100 MHz. (C) 1998 American Institute of Physics.