Imaging the Kirkendall effect in pyrite (FeS2) thin films: Cross-sectional microstructure and chemical features
| Autor: | Fabrice Leardini, Leonardo Soriano, Isabel J. Ferrer, Dietmar Leinen, Jan Ingo Flege, José R. Ares, Carlos Morales, Esmeralda Muñoz-Cortés, Eduardo Flores, Carlos Sánchez |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Consejo Superior de Investigaciones Científicas (España), Comunidad de Madrid, Ministerio de Economía y Competitividad (España), European Commission, Morales, Carlos [0000-0001-5890-1950], Flores, Eduardo [0000-0003-4769-0873], Leardini, Fabrice [0000-0002-2864-2369], Soriano, Leonardo [0000-0001-5715-376X], Ferrer, Isabel J. [0000-0003-2125-5865], Morales, Carlos, Flores, Eduardo, Leardini, Fabrice, Soriano, Leonardo, Ferrer, Isabel J. |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Polymers and Plastics Kirkendall effect 02 engineering and technology Substrate (electronics) engineering.material 01 natural sciences Impurity 0103 physical sciences Thin film 010302 applied physics Sodium doping Metals and Alloys PyriteTEM 021001 nanoscience & nanotechnology Microstructure Electronic Optical and Magnetic Materials Chemical engineering Ceramics and Composites engineering Grain boundary Pyrite Cross-sections 0210 nano-technology Stoichiometry |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | This investigation provides novel data on the structure and chemical composition of pyrite thin films and new hints concerning their formation mechanism. From TEM-HAADF data, it has been found that the films are composed of two different layers: one is very compact and the other one is quite porous with many voids separating a few groups of grains. This porous layer is always in direct contact with the substrate, and its thickness is quite similar to that of the original Fe film. The average size of pyrite grains is equal in both layers, what suggests that the same process is responsible for their formation. Concentration profiles of sulfur, iron and some impurities (mainly sodium and oxygen from the glass substrate) through both layers are given in this work, and thus chemical inhomogeneities of the films are proved by the obtained stoichiometric ratios (). Moreover, Na from sodalime glass substrates mainly accumulates at the pyrite grain boundaries and barely dopes them. The obtained results support the hypothesis that the iron sulfuration process essentially induces the diffusion of iron atoms, what leads to the porous layer formation as a manifestation of the Kirkendall Effect. Therefore, it seems that the same mechanisms that operate in the synthesis of surface hollow structures at the nanoscale are also active in the formation of pyrite thin films ranging from several tens to hundreds of nanometers. Members of MIRE Group acknowledge the financial support of the Spanish MICINN under project RTI2018-099794-B-I00. Authors also thank to Mr. F. Moreno for his technical assistance. E. Flores acknowledges the intramural CSIC project 2D-MeSes funding and the service from the MiNa Laboratory at IMN, and funding from CM (project SpaceTec, S2013/ICE2822), MINECO (project CSIC13-4E-1794) and EU (FEDER,FSE). Financial support through the project UMA18-FEDERJA-041 is gratefully acknowledged. |
| Databáze: | OpenAIRE |
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