FePt films fabricated by electrodeposition

Abstract

In this work, we have fabricated FePt films with a thickness in the range of 0.1-1 μm using the combination of electrodeposition and postannealing. FePt films with a composition around Fe50 Pt50 were formed by electrodeposition onto the Si (100) substrates with an underlayer of Au, Ag, or Cu, and subsequently annealed at a temperature in the range of 200-900 °C for 20 min. From our x-ray diffraction analysis, the L 10 FePt phase started to form after annealing at 400 °C for the film deposited on the Au underlayer. The highest coercivity (10 kOe) was found after annealing at 600 °C. When the FePt was deposited on the Ag underlayer, a high coercivity over 15 kOe with an out-of-plane anisotropy has been achieved after annealing at 700-800 °C. The magnetic anisotropy was associated with the crystallographic texture. The magnetic properties of FePt films deposited on the Cu underlayer were relatively poor with lower values of coercivity (4-5 kOe as the maximum coercivity), probably due to the large grain size. © 2007 American Institute of Physics.