Abstract
The thermal decomposition of almandine garnet from Zoltye Vody, Ukraine, has been studied using57Fe Mössbauer spectroscopy. Room temperature Mössbauer spectrum of the initial powdered sample is characterised by one doublet corresponding to Fe2+ in dodecahedral position 24c. In the room temperature spectra of all heated almandine samples, a doublet corresponding to γ-Fe2O3 nanoparticles appeared. Depending on experimental conditions (heating temperature and time), the additional spectral lines of α-Fe2O3 and ε-Fe2O3 were observed in Mössbauer spectra.
It is obvious that the thermal transformation of almandine garnet in air is related to the primary formation of γ-Fe2O3 superparamagnetic nanoparticles. γ-Fe2O3 nanoparticles are transformed into ε-Fe2O3 and consequently into α-Fe2O3 at higher temperatures. The mechanism and kinetics of the individual structural transformations depend on experimental conditions — mainly on the heating temperature and size of the particles.
Similar content being viewed by others
References
R. Zboril:The mechanism of Fe 2O3 formation during the thermal decomposition of intermediates of FeSO4·7H2O conversion, PhD thesis, Palacky University, Olomouc, 2000, p. 118.
R. Zbořil, M. Mašláň, D. Krausová, and P. Pikal: Hyperfine Interaction121–122 (1999) 497.
R. Zbořil, M. Mašláň and D. Krausová: inMössbauer Spectroscopy in Materials Science (Eds. M. Miglierini and D. Petridis). Kluwer Academic Publishers, Dordrecht, 1999, p. 49.
E. Tronc, C. Chanéac, and J. P. Jolivet: J. Solid State Chem.139 (1998) 93.
S. Mitra:Applied Mössbauer Spectroscopy Pergamon Press, Oxford, 1992, p. 313.
Powder Diffraction File 1997, International Center for Diffraction Data, Pennsylvania, U.S.A.
Author information
Authors and Affiliations
Additional information
Financial support from the Ministry of Education of the Czech Republic under project FRVS 154/00, from the Grant Agency of the Czech Republic under projects 202/00/0982 and 202/00/D091, is gratefully acknowledged.
Rights and permissions
About this article
Cite this article
Barcova, K., Mashlan, M., Zboril, R. et al. Thermal decomposition of almandine garnet: Mössbauer study. Czech J Phys 51, 749–754 (2001). https://doi.org/10.1023/A:1017618420189
Received:
Issue Date:
DOI: https://doi.org/10.1023/A:1017618420189