RT Journal Article
T1 Reaction Mechanism and Kinetic Model of Fe Thin Film Transformation into Monosulfides (FeS): First Step of the Fe Films Sulfuration Process into Pyrite
A1 Morales Sánchez, Carlos
A1 Pascual, Antonio
A1 Leinen, Dietmar
A1 Flores, Eduardo
A1 Muñoz Cortés, Esmeralda
A1 Leardini, Fabrice
A1 Ares Fernández, José Ramón
A1 Soriano de Arpe, Leonardo
A1 Jiménez Ferrer, Isabel
A1 Sánchez López, Carlos
K1 Hierro - Aleaciones
K1 Piritas
AB The sulfuration of metallic iron layers into pyrite (FeS2) is preceded by an initial stage characterized by the iron transformation into monosulfide, which acts as a precursor of the disulfide. This work presents a comprehensive reaction and kinetic model of the sulfuration reaction of metallic iron thin films into monosulfides when using a molecular sulfur (S2) atmosphere. By slowing down the sulfuration reaction, we have been able to follow in-situ the evolution of the transport properties (electrical resistivity and Seebeck coefficient) of the Fe films during their sulfuration reaction to monosulfides. We show that two different stages characterize this initial sulfuration: (1) the transformation of Fe into hexagonal pyrrhotite (Fe → Fe1-xSH), and (2) a partial crystallographic transformation of this hexagonal pyrrhotite into orthorhombic pyrrhotite (Fe1-xSH → Fe1- xSO). A two-step process can explain the pyrrhotite hexagonal phase formation, being firstly controlled by the surface adsorption of S2 on the external sample interface (S2/pyrrhotite) and secondly by the diffusion of Fe atoms through the formed pyrrhotite layer. By deducing the corresponding kinetic equations in terms of the experimental parameters (S2 partial pressure and thicknesses of the layers of present species), we can explain the evolution of the electrical resistance and Seebeck coefficient of the original Fe film during its transformation into monosulfide. At the same time, the appearance of the Kirkendall effect during the monosulfide phase formation is experimental and formally justified. The comprehensive description of this first stage of the complete sulfuration process of the Fe film into pyrite provides a layout to deeply discuss the influence of these intermedium phases on the final iron disulfide film characteristics and the appearance of potential film defects related to the experimental growth conditions.
PB American Chemical Society
YR 2022
FD 2022-08-03
LK https://hdl.handle.net/10630/38371
UL https://hdl.handle.net/10630/38371
LA eng
NO J. Phys. Chem. C 2022, 126, 13870−13883
NO https://openpolicyfinder.jisc.ac.uk/id/publication/7799
NO Spanish MICINN/RTI2018-099794-B-I00
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 5 mar 2026