ELECTRODEPOSITED CoNiFe ALLOY THIN FILMS FOR MAGNETIC RECORDING

Abstract

Alloy thin films of ternary system Co – Ni – Fe and binary systems Co – Fe , Co – Ni and Ni – Fe consisting of ~50 nm grains have been deposited by a simple and industrially viable technique of electrodeposition in galvanostatic mode on ITO-coated glass. Bath composition and current density have been varied to prepare films of different compositions and thus, in turn, obtain suitable composition for better magnetic properties. Further, an attempt has been made to deposit films in the presence of Mg 2+ in the bath and to study its linkage with the magnetic properties, i.e., saturation magnetic flux density, BS, and coercivity, HC. Our results clearly demonstrate that addition of Mg 2+ ions in the bath helps in increasing the BS considerably.

Potentiostatic Electrodeposition of Co-Ni-Fe Alloy Particles Thin Film in a Sulfate Medium

“…1(c)) at concentration of 0.005 M, the anodic peak (a 3 ) appears at a further negative region, approximately at -0.489 V, compared to the individual cobalt and nickel. During the reversed scan, it was observed the presence of two reduction peaks, c 3 and c 4 . The first peak (c 3 ) corresponds to the iron reduction from Fe 2+ i n t o iron metal at a potential of about -0.5 V which is significantly close to the Nernstian value.…”

“…In the last few years, intensive studies [2,3] have been done on these materials to explore their unique soft magnetic properties. New soft magnetic materials with greater performance are desirable due to rapid increase of areal density (bits per square inch of recording medium) of data storage in computer drives [4], advanced miniaturization and high capability electromagnetic devices in MEMS [5,6]. Numerous Co-based ternary alloys such as Co-Fe-B [7], CoFe-Cu [8] and Co-Ni-Fe [9,10] are among the potential candidates to serve the purpose.…”

“…The first peak (c 3 ) corresponds to the iron reduction from Fe 2+ i n t o iron metal at a potential of about -0.5 V which is significantly close to the Nernstian value. Further increase in negative potentials has resulted in the emergence of peak c 4 , which corresponds to the hydrogen ion reduction reaction [24]. 2+ ions concentration, the deposition is diffusionlimited over a wide potential range from c 5 to c 6 peaks.…”