2026-06-02T21:45:06Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/383712026-02-03T10:51:24Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Morales Sánchez, Carlos author Pascual, Antonio author Leinen, Dietmar author Flores, Eduardo author Muñoz Cortés, Esmeralda author Leardini, Fabrice author Ares Fernández, José Ramón author Soriano de Arpe, Leonardo author Jiménez Ferrer, Isabel author Sánchez López, Carlos author 2022-08-03 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. J. Phys. Chem. C 2022, 126, 13870−13883 https://hdl.handle.net/10630/38371 10.1021/acs.jpcc.2c02060 Hierro - Aleaciones Piritas Reaction Mechanism and Kinetic Model of Fe Thin Film Transformation into Monosulfides (FeS): First Step of the Fe Films Sulfuration Process into Pyrite