Electrodeposition and Properties of Fe-Based Magnetic Alloys

The goal of this work was to apply and extend a citrate-glycine complex of ferric ions based alkaline solution to generate a range of Fe-based alloy electrodeposits and nanostructures that could not be obtained otherwise. From a series of electrochemical experiments and characterization performed, electrolytes producing uniform Fe-based alloys with desired magnetic properties were achieved and reported. Systematic studies were carried out on binary (FeNi and FePt) and ternary (FeNiPt) iron group alloys relating their structure, magnetic properties with composition, thickness and annealing conditions.
Fabrication of L10-FePt nanodot arrays for bit patterned media (BPM) by electrodeposition from an alkaline solution was described, with an ultimate goal to achieve isolated bits of size ~10nm. In this thesis, a nanoimprinting technique was employed to form patterned substrate with 150nm pitch by collaborating with colleagues at Waseda University, Japan. Deposition and annealing conditions for FePt nanopatterns were studied and optimized. In particular, a patterned Fe48Pt52 (55nm) with a high coercivity of around 8.2kOe was formed by electrodeposition with subsequent heat treatment, demonstrating the capability of electrochemical processes to produce high performance FePt ferromagnetic nanodot arrays.
Electrodeposition of Fe-Ni-Pt thin films for applications in heat-assisted magnetic recording (HAMR) was also studied. An electrolyte based on the citrate-glycine complexes of ferric ions for the deposition process was investigated and optimized to generate a series of homogeneous FexNi50-xPt50 (0