Enhanced Magnetic Properties of Electrodeposited Co2FeSn Film with High Structural Order.

Near stoichiometric Co₂FeSn Heusler alloy films with a highly ordered L2₁ structure and mean grain size of 23 ± 1 nm have been prepared on a polycrystalline copper substrate for the first time by 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 c.c.⁻¹) 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 the Hubbard parameter U. [ABSTRACT FROM AUTHOR]