Fabrication of semi-epitaxial Fe microdots on GaAs (100) substrates

Fe thin films and micro-dots were deposited onto Si (001) and GaAs (100) substrates by a combinatorial approach of lithography and e-beam deposition techniques. The base pressure in the evaporation chamber was 1×10-6 mbar. 50nm and 5 nm of Fe was deposited with a deposition rate of 0.1 nm/sec onto Si and GaAs, respectively. Continuous films and microdots were covered with 5 nm Cr to prevent oxidation. In-plane interfacial uniaxial magnetic anisotropy has been observed in micro-dots. Room temperature coercivity of 925 Oe has been observed in out-of-plane direction. Effects of strain and interfacial phases on in-plane uniaxial anisotropy are discussed. Synthesized micro-dots could be the building blocks for next-generation magnetoelectronic devices.