Structure and composition of Au/Co magneto-plasmonic nanoparticles

Abstract

The fabrication of bimetallic magnetic nanoparticles (NPs) smaller than the size of single magnetic domain is very challenging because of the agglomeration, non-uniform size, and possible complex chemistry at nanoscale. In this paper, we present an alloyed ferromagnetic 4 ± 1 nm thiolated Au/Co magnetic NPs with decahedral and icosahedral shape. The NPs were characterized by Cs-corrected scanning transmission electron microscopy (STEM) and weretheoretically studied by Grand Canonical Monte Carlo simulations. Comparison of Z-contrast imaging and energy dispersive x-ray spectroscopy used jointly with STEM simulated images from theoretical models uniquely showed an inhomogeneous alloying with minor segregation. The magnetic measurements obtained from superconducting quantum interference device magnetometer exhibited ferromagnetic behavior. This magnetic nanoalloy in the range of single domain is fully magnetized and carries significance as a promising candidate for magnetic data recording, permanent magnetization, and biomedical applications.

Multimodal Magnetic-Plasmonic Nanoparticles for Biomedical Applications

“…For example, Brusts method was used by Bhattarai et al to produce bimetallic magnetic plasmonic Au/Co. nanoparticles ( Figure 6) [55]. …”

Structural Analysis of AuPdAu Nanocubes via Aberration-Corrected STEM and Nanobeam Diffraction

“…18,26 The lattice mismatch between Au and Pd is 4.6 % given by their different lattice parameters (4.07 Å and 3.88 Å respectively), 28 and therefore the formation of stacking faults is the optimum way to release the stress and reduce the system energy. 29,30 Examining Figure 3 (b), we can also observe that the FFT in the inset, which is representative of the area marked by the yellow square, shows that, apart from the main reflections, additional weaker reflections appear, as marked by red circles. Moreover, by examining the line profile marked with red line in Figures 3 (b) and (c), we can observe the 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 presence of alternating Au and Pd atoms in a single atomic column, but on short range distances.…”

Synthesis and Structural Characterization of Ferromagnetic Au/Co Nanoparticles

“…The detailed explanation about the magnetic property is presented in our previous report. 17 It should be noted that Au/Co NPs present ferromagnetic behavior with coercive field and retentive magnetization even though the size is < 5nm.…”