Epitaxial Fe(1-x)Gax/GaAs structures via electrochemistry for spintronics applications

In this study, thin films of Fe83Ga17 (a giant magnetostrictive alloy) were grown on single-crystalline n-GaAs (001) and polycrystalline brass substrates via electrochemical synthesis from ferrous and gallium sulfate electrolytes. Extensive structural characterization using microdiffraction, high-resolution omega - 2 theta, and rocking-curve analysis revealed that the films grown on GaAs(001) are highly textured with < 001 > orientation along the substrate normal, and the texture improved further upon annealing at 300 degrees C for 2 h in N-2 environment. On the contrary, films grown on brass substrates exhibited < 011 > preferred orientation. Rocking-curve analysis done on Fe83Ga17/GaAs structures further confirmed that the < 001 > texture in the Fe83Ga17 thin film is a result of epitaxial nucleation and growth. The non-linear current-voltage plot obtained for the Fe-Ga/GaAs Schottky contacts was characteristic of tunneling injection, and showed improved behavior with annealing. Thus, this study demonstrates the feasibility of fabricating spintronic devices that incorporate highly magnetostrictive Fe(1-x)Gax thin films grown epitaxially via electrochemistry. (C) 2012 American Institute of Physics. [doi:10.1063/1.3670514]