Effect of Dopants on the Microwave Magnetic Characteristics of FeCoBM-Al_2O_3 Soft Magnetic Thin Films

摘要

A series of FeCoBM (M=Nb, Zr, Hf, Mo, Ta, Ti)-Al_2O_3 films were prepared on glass and polymer substrates by means of RF magnetron co-sputtering. Effect of dopants on the soft magnetic properties and microwave magnetic characteristics of FeCoBM-Al_2O_3 Thin Films were studied. To further tailor the magnetic characteristics of the films, the (Fe_(40)Co_(40)B_(20))_(94.5)Hf_(2.5) -(Al_2O_3)_3 film was annealed at 200 to 400°C for 60 min. As a consequence, the (Fe_(40)Co_(40)B_(20))_(94.5)Hf_(2.5)-(Al_2O_3)_3 film annealed at 350°C exhibit excellent properties with high saturation magnetization of 1197 kA/m, high resonant frequency of 1.76 GHz, and the real part of permeability is about 600, which is maintained up to 1.5GHz. These results show that the presented films possesses potential in designing micro-magnetic devices for Monolithic Microwave Integrated Circuit (MMIC) and surface mount technology (SMT)industry.