Self-ordered magnetic α-FeSi2 nano-stripes on Si(111)

We fabricated self-assembled one-dimensional alpha-FeSi2 magnetic nano-stripes, using solid phase epitaxy of similar to 1 monolayer Fe on vicinal Si(111) surfaces followed by a 550 degrees C annealing. Structural and magnetic properties were investigated by scanning tunneling microscopy and superconducting quantum interference device magnetometry, respectively. The nano-stripes show superparamagnetism at room-temperature and at 4K coercivity about 3 times higher along the long nano-stripe [11 $$(2) over bar] direction than along the perpendicular [(1) over bar 10] one. The calculated magnetic moment at 4K was similar to 3.3 mu(B)/Fe atom, implying a significant ferromagnetic coupling of the Fe atoms in the system. Such nano-stripes may be useful in high-density magnetic memory storage and spintronics devices. (C) 2013 AIP Publishing LLC.