Selective‐area growth and magnetic reversals of ferromagnetic nanoclusters on semiconducting substrate for magnetic logic applications (Phys. Status Solidi B 9/2015)

Selective‐area metal‐organic vapor phase epitaxy is used by Hara and Komagata (pp. 1925–1933 ) as a bottom‐up formation approach (see schematic illustration of sample preparation on the cover) to fabricate ferromagnetic MnAs nanocluster (NC) composite arrays in which two NCs are formed in close proximity at an angle of 120° and with a spatial gap of around 20 nm on GaAs (111)B substrates (cf. the scanning electron microscope, SEM, and atomic force microscope, AFM, images bottom left). Magnetic reversal of the NCs in the composite arrays is observed depending on the strengths and directions of the applied external magnetic fields, B , at room temperature. Magnetic force microscopy (MFM) characterization results show that the magnetic reversals are independently controlled in one of the two NCs in the composites, i.e., in the free NCs (on the right: MFM images showing the dependence of magnetic reversals on the B direction). The authors use these results to propose possible application to magnetic logic operations by designing the NC size, shape, and arrangement to control the magnetization directions in the NCs in the composites.