Novel structures and physics of nanomagnets (invited)

Abstract

Nanoscale magnets with characteristic dimensions in the range of 1–100 nm are important in several areas of nanoscience and technology. First, this length scale spans the typical important dimensions of exchange lengths and domain-wall widths, which means that significant control of magnetic properties can be obtained by varying grain or particle dimensions. Second, the nonequilibrium synthetic processes used for clusters, particles, and films, often lead to new real-space crystal structures with completely novel spin structures and magnetic properties. Third, a basic-science challenge in this class of matter involves the spin-polarized quantum mechanics of many-electron systems containing 10–10 000 atoms. Finally, the materials under study may have important future applications in high-density data storage, ultra-small spintronic devices, or high-energy magnetic materials. In this article, we discuss our recent work on novel Fe-Au nanoclusters, MnAu-Mn core-shell structures, and complex high-anisotropy Co-rich intermetallic compound clusters. We also present new results on Fe-based alloys including the magnetic properties of semiconducting FeSi2 nanoclusters and spin correlations in FeGe nanocluster films.

Magnetic excitations in molecular magnets with complex bridges: the tetrahedral molecule Ni4Mo12

“…The physical properties, such as energy spectra, susceptibility, etc., of magnetic clusters at the nanoscale depend on their size, shape and the presence of different bondings among the constituent chemical elements and thus the distribution of ligands between the magnetic ions (for more details see [1][2][3][4] and references therein). Some prominent examples are Mn based magnetic compounds [5][6][7][8][9][10][11] and spin clusters with Ni magnetic ions [12][13][14][15] .…”

Charge distribution and Fermi level in bimetallic nanoparticles

“…In recent years, bimetallic nanoparticles have received increasing attention due to their promising electrocatalytic, [1][2][3] catalytic, [4][5][6][7][8] magnetic, 4,9,10 and optical properties. 4,11 The interaction of nanoparticles with their environment can, sometimes drastically, shift the Fermi level of electrons in the nanoparticles, influencing their chemical and electrochemical properties, as highlighted in a recent review.…”

Thickness dependence of exchange coupling in epitaxialFe3O4/CoFe2O4Lavorato1, Winkler2, Rivas‐Murias3 et al. 2016Phys. Rev. B425362View full textAdd to dashboardCite

“…Exchange coupling in bimagnetic nanostructures has led to new applications [1][2][3][4][5] and new materials can be designed by changing the nature of each component [6], their relative size [7,8], or tuning the interface interactions [9,10]. For example, nanoparticles with core/shell structures have been synthesized seeking new permanent magnets [11,12], devices for highdensity data storage [12], nanoheaters for hyperthermia [13], or image contrast agents [5]. At the same time, hard/soft bilayer thin films are of great interest for spin filtering and magnetic tunnel junctions [14,15].…”