MAGNETIC-PROPERTIES AND CORROSION-RESISTA NCE OF FE-TA-C SPUTTERED THIN-FILMS PREPARED UNDER ARGON ATMOSPHERE CONTAINING NITROGEN GAS

The magnetic properties, the thermal stability, and the corrosion resi stance of Fe-Ta-C thin films prepared in an atomsphere containing N-2 were studied. As the N-2 content in the sputtering gas is increased, B s and mu decrease, while He and lambda s increase. A film prepared in Ar+N-2 (1.5 vol%) has Bs of about 1.4 T, and mu (at 1 MHz) higher than 2000. A film prepared in Ar+N-2 (2 vol%) has He of 80 A/m, and lambda s of 1.4 x 10(-6). Fe-Ta-C thin films produced in an atomsphere conta ining N-2 have a high thermal reliability. After thermal treatment at 873 K, the soft magnetic properties of Fe-Ta-C thin film produced in t he atomsphere containing N-2 did not change, while that of Fe-Ta-C thi n film produced in pure Ar atomsphere changed, namely, He increased an d mu decreased. The corrosion resistance was measured by change of Bs. The value of Bs of the Fe-Ta-C thin film prepared in an atomsphere co ntainning N-2 did not change after being immersed in pure water for 3. 96 x 10(5) s. Furthermore, this film has a high corrosion resistance i n pure water with Ar bubbling for 1800 s. However, Bs of Fe-Ta-C thin film prepared in pure Ar atomsphere decreased to 65% of the initial va lue. After immersing the Fe-Ta-C thin film prepared in Ar+N-2 (0.5 vol %) in 0.01 N NaClaq for 3.96 x 10(5) s, Bs decreased to 75% of the ini tial value, while in the case of Fe-Ta-C thin film prepared in Ar+N-2 (5 vol%), Bs decreased to 95% of the initial Bs.