Core-Shell Au/Fe3o4 Nanocomposite Synthesized By Thermal Decomposition Method: Structural, Optical, And Magnetic Properties

Core-shell structure Au@Fe3O4 nanoparticles was synthesized via a thermal decomposition method, evidencing through interplanar atomic distances of similar to 0.23 nm and similar to 0.48 nm finding in the center and the shell of the particles, matching to the (1 1 1) Au and (1 1 1) magnetite planes, respectively. The nanocomposite has an average diameter of the core of similar to 10.5 nm and a thickness of the shell of similar to 1.85 nm, accessed by TEM. X-ray diffraction carried out on the sample shows the crystal structure of fcc Au and fcc Fe3O4 without a spurious crystalline phase. Besides, Rietveld refinement displays an outer diameter of similar to 8.1 and similar to 12.3 for the core and shell, respectively, the latter using the Scherrer constant of 0.9 and 1.43, respectively. The UV-vis characterization result shows a surface plasmon resonance spectra of Au@Fe3O4 nanoparticles at similar to 540 nm, which advise a successful core-shell coupling of Au and the Fe3O4. Finally, the magnetic response displays a system with a superparamagnetic state at room temperature and with a distribution of blocking temperatures associated with the enhanced surface contribution related to the hollow magnetite structure's inner and outer surface. From the mean TB, the effective magnetic anisotropy K-eff 1.7 x 10(4) J/m(3) was obtained, which is in agreement with the expected for the magnetite phase.