Enhanced Magnetic Properties of Electrodeposited Co₂FeSn Film with High Structural Order

Abstract

Near stoichiometric Co2FeSn Heusler alloy films with a highly ordered L2 1 structure and mean grain size of 23 ± 1 nm have been prepared on a polycrystalline copper substrate for the first time by an electrodeposition route. Deposition potential -4.0 V yielded the stoichiometric alloy composition in the potentiostatic mode. The highly disordered as-deposited alloy film crystallized into the ordered stable Heusler alloy structure upon heat treatment under vacuum. The heat-treated film exhibited the highest magnetic moment (5.18 ± 0.04 μB/f.u. at 5 K) and Curie temperature (1123 K) ever achieved in this alloy in any form. The very high value of Keff (~106 erg/cc) obtained for this alloy makes this alloy promising for high-density magnetic recording application. Ab initio studies using GGA+U approach provide information on the minority gap near the Fermi level and its tunability as a function of the electron correlation factor represented by Hubbard parameter U.

Electrodeposited Fe2CoSn Thin Film with Enhanced Structural and Magnetic Properties

“…Composition, structure and morphology.-The elemental composition of the film was optimized by varying the deposition potential applied between working and reference electrodes while keeping all other parameters fixed. 23 At the optimized potential of −4.0 V, the amounts of precursor metal sulphates were adjusted to get the stoichiometric composition of Fe:Co:Sn as 2:1:1. The measured composition of synthesized HA film is 49.2:26.8:24.0, which is very close to the stoichiometric composition of Fe 50 Co 25 Sn 25 .…”