Rev.Adv.Mater.Sci. (RAMS)
No 1/2, Vol. 52, 2017, pages 70-81


I.N. Markova, I.Z. Zahariev, V.L. Milanova, D.I. Ivanova,
M.B. Piskin, L.B. Fachikov and E. Hristoforou


Intermetallic (Co-Sn, Ni-Sn, Co-Ni) nanoparticles have been synthesized through a wet chemical reduction with NaBH4 in aqueous solutions of the chloride salts of Co, Ni, and Sn at room temperature. Also nanocomposite materials have been obtained in-situ using the same nanoparticles synthesis method but applying a template technique and using carbon-based support. The ratio of the metallic components has been chosen according to the phase diagrams of the relevant binary (Co-Sn, Ni-Sn, Co-Ni) systems: Co: Sn=35:65, Ni: Sn=45:55, Co: Ni=50:50. Graphite has been used as a support. To avoid the nanoparticle aggregation b-cyclodextrin has been added to the reaction solutions. The morphology, elemental and phase composition of the synthesized intermetallic nanocomposites have been investigated with SEM, EDS, and XRD respectively. The nanoparticles are different by shape and in size and exhibit a tendency to aggregate due to the unsaturated nanoparticle surface and the existing magnetic forces. The nanoparticle morphology is typical for an alloyed material. The formed phases are in accordance with the respective binary system phase diagrams: phases of CoSn and CoSn2 for the Co-Sn (Co:Sn=35:65) nanoparticles, phases of Ni3Sn4, Ni3Sn2 and Ni3Sn for the Ni-Sn nanoparticles (Ni: Sn=45:55), phases of Co and Ni for the Co-Ni nanoparticles (Co: Ni=50:50). The prepared nanopowders (Co-Sn, Ni-Sn, Co-Ni) and their carbon-containing nanocomposites have been studied by FTIR spectroscopy in the mid-IR region from 4000 to 400 cm-1. On the basis of the collected FTIR spectra, respectively bands of absorption with peaks at the relevant frequencies the kind of vibrations (symmetric or asymmetric stretching and bending) of the created chemical bonds in different atom groups such as COH, CH2, OH, H2O, C=C, COOH, BO3, BO4, Me-O (Me=Co, Sn, Ni) have been determined.

full paper (pdf, 1376 Kb)