Spinel Ferrite Core-Shell Nanostructures by a Versatile Solvothermal Seed-Mediated Growth Approach and Study of Their Nanointerfaces

0477901 - ÚACH 2018 RIV US eng J - Journal Article
Angotzi, M. S. - Musinu, A. - Mameli, V. - Ardu, A. - Cara, C. - Nižňanský, Daniel - Xin, H. L. - Cannas, C.
Spinel Ferrite Core-Shell Nanostructures by a Versatile Solvothermal Seed-Mediated Growth Approach and Study of Their Nanointerfaces.
ACS Nano. Roč. 11, č. 8 (2017), s. 7889-7900. ISSN 1936-0851. E-ISSN 1936-086X
Institutional support: RVO:61388980
Keywords : ferrite * core-shell nanoparticles * cofe2o4/nife2o4 * EELS * EDX
OECD category: Inorganic and nuclear chemistry
Impact factor: 13.709, year: 2017

An easy, low-cost, repeatable seed-mediated growth approach in solvothermal condition has been proposed to synthesize bimagnetic spinel ferrite core-shell heterostructures in the 10-20 nm particle size range. Cobalt ferrite and manganese ferrite nanoparticles (CoFe2O4 and MnFe2O4) have been coated with isostructural spinel ferrites like maghe. mite/magnetite, MnFe2O4, and CoFe2O4 with similar cell parameters to create different heterostructures. The conventional study of the structure, morphology, and composition has been combined with advanced techniques in order to achieve details on the interface at the nanoscale level. Clear evidence of the heterostructure formation have been obtained (i) indirectly by comparing the Fe-57 Mossbauer spectra of the core shell samples and an ad hoc mechanical mixture and (ii) directly by mapping the nanoparticles' chemical composition by electron energy loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDX) in the scanning transmission electron microscopy mode (STEM). In addition, chemical-sensitive electron tomography in STEM-EDX mode has been applied in order to obtain detailed 3D images with a sub-nanometer spatial resolution.
Permanent Link: http://hdl.handle.net/11104/0275313