Researcher of the Year 2018 - Professor T. Venkatesan. The advanced materials community would like to take this opportunity to pay rich tributes to Professor T. Venkatesan for his pioneering research and notable contributions to nanoscience and nanotechnology. Advanced Materials Letters have been selected his photo for the cover of this special year-end issue.
Nucleation and growth of carbon nanoforms on the surface of metallic plate-substrates and the mechanism of their doping with the clusters of ferromagnetic atoms
E. Kutelia1*, L. Rukhadze1, N.Jalabadze1, T. Dzigrashvili1, O. Tsurtsumia1, D. Gventsadze2
1Republic Centre for Structure Researches of Georgian Technical University, 77 Kostava Str., Tbilisi 0175, Georgia
2R. Dvali Institute of Machine Mechanics, 10 Mindeli Str., Tbilisi 0186, Georgia
Adv. Mater. Lett., 2018, 9 (12), pp 867-871
Publication Date (Web): Sep 14, 2018
Copyright © 2019 VBRI Press
The present work deals with the special experiments on SEM-EDX study of morphology, chemical composition and topological transformations of the initial ground surface of the bulk iron plate-substrate after its interaction with the ethanol vapor pyrolysis products at high temperatures in the closed-loop and open cycle reactors. Our experiments have shown that the mechanism of formation of Fe clusters-doped CNFs on plate-substrate surfaces may be represented as a process, the first stage of which is a protonation of the substrate subsurface layers caused by diffusion of hydrogen atoms facilitating the formation of 3D nano-groups of Fe atoms assembled in the characteristic clusters with magic numbers of atoms, depending on the thermodynamics of the metal. The spontaneous coalescence of these clusters into giant Fe-clusters at comparatively low temperatures and formation of iron nano-droplets at comparatively high temperatures results in the formation of a nanopatterned surface with the uniformly distributed catalytic centers of CNFs nucleation. The second stage of the process is a nanoparticle-guided growth through the VLS or VS (at low temperatures) growth mechanisms in which the one cluster provides nucleation of only one CNF particle so that the sizes of the nucleation centers determine the basic size of the CNF nanoparticles.
Doped CNFs, clusters, growth mechanism, metal plate-substrate, SEM-EDX.