Combined Macro/Nanoscale Investigation of the Chemical Vapor Deposition of Fe from Fe(CO)₅

Abstract

Experiments and computations are performed to model the chemical vapor deposition of iron (Fe) from iron pentacarbonyl (Fe(CO)5). The behavior of the deposition rate is investigated as a function of temperature, in the range 130–250 °C, and pressure in the range 10–40 Torr. Furthermore, the evolution of the surface roughness is correlated with the deposition temperature. By combining previously published mechanisms for the decomposition of Fe(CO)5, a predictive 3D macroscale model of the process is built. Additionally, a nanoscale and a multiscale framework are developed for linking the evolution of the surface of the film with the operating conditions at the reactor scale. The theoretical predictions from the coupled macro/nanoscale models are in very good agreement with experimental measurements indicating poisoning of the surface from carbon monoxide and decrease of the film roughness when temperature increases.

Chemical Vapor Deposition of Al13Fe4 Highly Selective Catalytic Films for the Semi‐Hydrogenation of Acetylene

“…It is attributed to the rough microstructures of the two initial layers, reported in Refs. for Al and Fe films, respectively, further perturbed by the extended interdiffusion during annealing. In that lamella, no pure Al regions are observed, confirming that diffusion is effective across the whole stack.…”

“…At T d higher than 170 C angular and sharply-faceted grains are first formed followed by films with an acicular morphology above 200 C. Details on the microstructure and the growth rate of the Fe films can be found in Ref. [19]. Based on these results on the growth rate and on the microstructure of the two elements, bi-layers were processed by first depositing Al at T d and P d 180 C and 5 Torr followed by deposition of Fe at 140 C and 40 Torr.…”

“…XPS is now used for the characterization of the surface composition. The initial surface composition of the as-processed film exposed to ambient air is Al(12.7)Fe(2.3)O(66.0)C (19) in at.%. This surface composition is the one relevant to the initial condition of the catalysis test.…”

“…This work is based on our recent investigations of the kinetics and the transport phenomena of the CVD of unary Al [17,18] and Fe. [19] We characterize the structure and composition of the films, we report preliminary results on the semihydrogenation of acetylene with the obtained Al-Fe films as catalysts and we propose correlations between the catalytic behavior and the characteristics of the films.…”

“…In this paper, we describe an innovative route for the processing of Al 13 Fe 4 films by sequential CVD of the two metals followed by in situ thermal annealing to stimulate reactive diffusion. This work is based on our recent investigations of the kinetics and the transport phenomena of the CVD of unary Al and Fe . We characterize the structure and composition of the films, we report preliminary results on the semi‐hydrogenation of acetylene with the obtained Al‐Fe films as catalysts and we propose correlations between the catalytic behavior and the characteristics of the films.…”