Striped domains in soft magnetic FeNiN thin films

摘要

FeNiN thin films with good soft magnetic properties were synthesized on Si (100) substrates at 473K by RF magnetron sputtering; all the films have a thickness of around 500 nm. The dependence of phase structure and magnetic properties on nickel concentrations and RF power were systematically investigated. With increasing nickel contents from X-Ni = 5.0% to X-Ni = 65.5%, FeNiN thin films deposited at P-N2 = 10.0% turn from a main bcc alpha-( Fe, Ni) phase coexisting with. gamma'- phase to fcc gamma'-(FeNi3)(4)N phase. With the RF power larger than 160W, the samples deposited at P-N2 = 3.0% all show clear reproducible striped domains at the films' surfaces, which is explained by the high enough perpendicular anisotropy and the small stress in the film. A completely ordered structure of (FeNi) N-0.0324-phase forms at PW = 300W. The FeNiN thin films prepared at different RF power show smooth surfaces and good soft magnetic properties compared with corresponding FeN compounds. The optimum soft magnetic properties with MS of similar to 1900 emu cm(-3), H-C of similar to 1Oe are obtained at P-N2 = 3.0% and P-W = 300W at 473 K.