Switching dynamics of morphology-structure in chemically deposited carbon films - A new insight

Carbon is one of the most investigated materials and shows chaotic behavior in terms of evolving structure. Synthesizing carbon materials largely depend on the deposition technique, process parameters, condition of substrate surface and ratio of the gaseous chemistry. A variety of techniques have been employed to depositing carbon films from various gaseous mixtures to different substrate materials. In this study, carbon thin and thick films are discussed for different techniques known as hot filament chemical vapor deposition and microwave plasma chemical vapor deposition where their synthesis process has been explained in a new context. Here, we discuss attained dynamics of atoms (or their tiny grains) amalgamating into a particular phase of grain or crystallite and electron-dynamics responsible for binding atoms in the formation of all sorts of tiny grains, grains and crystallites controlling overall morphology-structure of films thickness at few nanometers to several microns. Carbon atoms when in solid state, on amalgamation at flat surface result into bind under uniform electron-dynamics and when the amalgamation is at uneven surface, (even at atomic level) they result into bind under non-uniform electron-dynamics. Where binding of atoms is at uniform electron-dynamics, a graphitic structure evolves following by different modifications into other carbon phases depending on the orientation of electron states with respect to centre of inner part of atom known as nucleus. Substrates under appropriate surface defects or abrasion result into an improved rate of nucleation of tiny grains, hence, their increased rate of growth. This study embarks on unexplored science of carbon films where in addition to localized process parameters nature of substrate also influence dynamics of formation of tiny clusters, grains and crystallites at their initial stage of formation. Our results and discussions enlighten us to revisit the nucleation and growth mechanisms of different sorts of films deposit at any scale and at any substrate surface constituting different composition.

(a1) diamond primitive cell, (a2) amalgamation of tiny grains and their sticking, (a3) grain in thin elliptical morphology, (a4) grain in needle-like shape and (a5) grain in lengthy needle-like shape, (b1) amalgamation of several tiny grains (morphology like tiny cluster) into coarse ballas morphology of crystallite and (b2) amalgamation of several tiny grains (morphology like needle) into coarse ballas morphology of crystallite, (c1) bottom-to-bottom binding of tetrahedron structure in pyramidal-like morphology, (c2) tetrahedron structure of grain/crystallite, (c3) transformation of tetrahedron structure into two-dimensional structure, (c4) transformation of tetrahedron structure in cube shape (cubic structure) and (c5) contaminated structure of crystallite comprising different phases, (d1) modification of amalgamated carbon atoms into tetrahedron primitive cell, (d2) binding of tetrahedron primitive cells under identical attained dynamics, (d3) crystallite of tetrahedron structure revealing pyramidal-like morphology, (e1) two-dimensional structure, (e2) elongation of two-dimensional structure and (e3) formation of smooth elements while travelling photons of hard X-rays and their binding under low energy photons.258