ELECTRODEPOSITION OF HIGH resistance measurements. The resistivity of DC CoFe

MAGNETIC MOMENT CoFe BASED electrodeposit was 30 µ cm, and DC CoFeV µΩ ALLOYS electrodeposit was 58 cm; incorporation of ~2wt% vanadium almost doubled the electrical resistivity of CoFe

electrodeposits. Electrical resistivity of PC CoFeV was 66 B.Y. Yoo, M. Schwartz and K. Nobe µΩ cm, slightly higher than DC CoFeV electrodeposits. Magnetic properties obtained for 2V-Permendur Department of Chemical Engineering, University of (49CO49Fe2V) were as follows : Hc ~6Oe, Bs ~2.3T and California, Los Angeles, CA 90095-1592 Br ~ 1.5T (after annealing). These preliminary results shows the promise of CoFeV thin film electrodeposits to INTRODUCTION achieve high performance soft magnetic properties of Hc < The high magnetic moment soft magnetic thin film is 1Oe, Bs ≥ 2.4T and ρelect > 100µΩcm. one of the important requirements for the fabrication of magnetic storage and MEMS devices. Permalloy ACKNOWLEDGMENT (80Ni20Fe) thin films, one of the most successful soft magnetic materials due to its low and good corrosion resistance can be readily fabricated by 100 electrodeposition (1). Next generation recording heads and magnetic MEMS, however, require materials with 10

higher magnetic moment so that considerable attention has 2 m been directed to the development of new CoFe based c Ω Ω Ω Ω k

/ magnetic alloys (2). p

R 1 Addition of vanadium (2wt.%) to 50Co50Fe magnetic (Permendur) substantially increases ductility and electrical resistivity with little degradation of 0.1 magnetic properties (3). Because of magnetic properties, CoFe/DC CoFeV/DC CoFeV/PC Permalloy/DC such as high magnetic , high Curie temperature, Materials / Current Source and low coercivity, it is used for high temperature applications such as cores for aircraft electric Figure 1. Corrosion resistance of CoFe, CoFeV, and generators (4). Permalloy with DC, and CoFeV with PC

In this paper, the results of electrodeposition 80 studies of high magnetic saturation CoFeV alloys are m presented including magnetic properties, microstructure c Ω Ω Ω Ω µ µ µ µ

60 /

and surface morphology. y t i v i t s

i 40 s e

EXPERIMENTALS r

l a c

i

r 20 t

To investigate the relationship between deposit c e l composition and magnetic properties and microstructure, E 0 the concentration of Co(II) and Fe(II) were varied from CoFe/DC CoFeV/DC CoFeV/PC Permalloy/DC 0.15M to 0.287M and 0.013M to 0.15M, respectively, Materials / Current Source keeping total group metal concentration ([Fe(II)]+[Co(II)]) at 0.3 M. The concentration of vanadyl Figure 2. Electrical resistivity of CoFe, CoFeV, sulfate was kept constant at 0.17 M. Corrosion resistance and Permalloy with DC, and CoFeV with PC of electrodeposit in 0.5M NaCl solutions was determined by IS. This work was supported by the DARPA MEMS program (BT639910020) and an NSF XYZ on a chip program. RESULTS AND DISCUSSION REFERENCES

Figure 1. shows the corrosion resistances of CoFeV deposits with direct current and pulse current 1. P.C. Andricacos, C. Arana, J. Tabib, J. Dukovic comparing Permalloy and CoFe deposits. As shown in the and L. T. Romankiw, J. Electrochem. Soc., 136, figure, corrosion resistance increased in the sequence of 1336 (1989). CoFe