Thermal decomposition kinetic study of Fe5C2 nanoparticles

Autor: Saeed Kamali, Seyed Abbas Shojaosadati, S. Sahebian, Fatemeh Ahmadpoor, Jacqueline A. Johnson, Fatemeh Najarnia
Rok vydání: 2022
Předmět:
Zdroj: Journal of Physics and Chemistry of Solids. 161:110436
ISSN: 0022-3697
DOI: 10.1016/j.jpcs.2021.110436
Popis: In this study, the thermal stability and decomposition kinetics of Hagg iron carbide nanoparticles synthesized via a wet chemical method have been investigated. Results of Mossbauer spectroscopy were in consonance with x-ray diffraction to prove the formation of Fe5C2 nanoparticles. The activation energy of the transformation was evaluated by thermogravimetric analysis, performed at different heating rates from room tempearture to 573 K, employing the Flynn-Wall-Ozawa and Coats-Redfern models. Using the Criado model, degradation kinetics was determined to be a three-dimensional diffusion type. Thermal x-ray analysis, high resolution transmission electron microscopy, and vibrating sample magnometer measurements were performed both before and after thermal treatment of the nanoparticles to compare phase structure, morphology, and magnetic properties. Results show that the high magnetic, high density Hagg iron carbide with a core-shell structure converts to the lower density magnetite with moderate magnetization and core shell structure.
Databáze: OpenAIRE