Superlattices of Co₂MnAl and Fe₂MnAl Heusler Alloys

MBE growth and properties of short period superlattices of Co2MnAl and Fe2MnAl have been studied. Superlattices with periods between one and two unit-cell of the Heusler compound were grown on Ge (111) and (001) substrates by sequentially depositing atomic layers of the constituent elements, instead of co-deposition of each ternary alloy. Multiple superlattices with different elemental stacking sequences and the same average composition were grown on the same substrate under the same conditions by the use of precision shadow masks, in order to explore the potential for artificially sequenced complex materials and functionalities. Growing surface was probed in situ by realtime scanning reflection high energy electron diffraction. Sample structure, composition, and magnetic properties were characterized by x-ray diffraction, energy dispersive x-ray spectroscopy, and magneto-optical Kerr effect, respectively.