Soft Magnetic Properties of High-Bs FeTa-N-O Films

Magnetic thin films of FeTa-N-O were prepared by using facing-target type dc magnetron sputtering in Ar+N
₂
+O
₂
plasma. The magnetic and structural properties were investigated as a function of the flow rates of the O
₂
and N
₂
introduced into the argon atmosphere. A high B
_s
(19 kG) and soft magnetic properties (H
_c
≤0.3 Oe, μ≥3000) were obtained for a wide range of O
₂
and N
₂
flow rates, and were retained after high-temperature (600°C) annealing. X-ray diffraction patterns of α-Fe (110) revealed that the soft magnetic films consisted of fine grains. The addition of Ta and N
₂
together with 02 in small amounts was highly effective for improving the soft magnetic properties and thermal stability. It decreased the post-annealing magnetic anisotropy and prevented the growth of α-Fe grains.