Magnetism in nanoparticles of semiconducting FeSi2

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

“…These findings are in accord with a few other reports on SPM in nanostructure arrays, by us 25 and other groups. [44][45][46][47] As expected from the model of the shape-induced inplane azimuthal alignment of the magnetic moments (generated by Fe-rich defects in a 1D chain-like fashion along the MNSt length 7,25,26 ), the coercivity at 4 K along the long MNSt ½11 2 axis was significantly higher than in the perpendicular ½ 110 direction [see Fig. 2].…”

“…[1][2][3][4][5][6] Reduced crystal size, and often dimensionality, may lead to unique structural and physical properties, quite different from those in the bulk state. [1][2][3][4][5][6][7][8] Tight dependence between the nanostructure structural (crystalline, shape, surface, etc) anisotropy and complex anisotropic behavior of its magnetic properties, facilitate ongoing research effort aimed at fabrication, measurements, and understanding the overall physics and materials science of one-dimensional (1D) nanostructures, including magnetic nano-stripes (MNSt), [9][10][11][12][13] where various anisotropies can be significant and in competition with one another. [14][15][16][17] Thus, in principle, one should be able to tune magnetic behavior of a nanostructure array by modifying the mean size and shape of the individual nanostructures in the array and/or their number density and geometrical arrangement.…”

“…Fe-silicide and other nano-materials with magnetic properties uniquely defined by their size, shape, and ordering, pave the way to utilization in high-density magnetic memory storage devices and spintronics. [5][6][7]24 The Fe-silicide nano-stripes were grown on 4 -miscut vicinal Si(111) wafers, in an ultra-high vacuum (UHV) variable-temperature scanning tunneling microscope (VT-STM) by Omicron Nanotechnology GmbH, equipped with low-(LEED) and reflection high-(RHEED) energy electron diffraction. In UHV (base pressure 1 Â 10 À8 Pa), after thorough degassing, the oxide was evaporated by repeated flashes at 1150-1200 C, and the clean Si surface slowly cooled until well-ordered (7 Â 7) reconstruction appeared in diffraction and STM.…”

The effect of Fe-coverage on the structure, morphology and magnetic properties of α-FeSi2nanoislands

“…We demonstrate that such magnetic properties can indeed be tuned to some degree by controlling the initial Fe-coverage and, consequently, the morphological evolution of the Fe-silicide nanoisland arrays. Although there have been a few reports on this topic [2,18,19,43], we draw a direct and explicit linkage between the physics (magnetic properties) and the microscopic materials science on the nanoscale (structure, morphology, lateral ordering, etc) of the α-FeSi 2 nanoislands. Since these nanoislands exhibit a non-bulk-like SPM behavior, and are metallic in nature, they are expected to become a promising material for high-density magnetic memory storage devices [6].…”

MAGNETIC PROPERTIES OF Fe0.95Co0.05Si2 SEMICONDUCTING FILM

“…16 Recently, Hamdeh et al suggested that the chemical-disorder can induce the magnetism in nanoparticles of β-FeSi 2 using the Mössbauer spectroscopic analysis. 17 Hattori et al also observed the formation of the ferromagnetic interface (Fe 3 Si) between the β-FeSi 2 film and Si substrate owing to the chemical-disorder at the interface. As a result, the β-FeSi 2 /Fe-rich-silicide/Si heterostructure could be one of the candidates for spintronic and unique optical devices.…”