%0 Journal Article %1 WOS:000223960700014 %A Ferreira, OP %A Alves, OL %A Gouveia, DX %A Souza, AG %A de Paiva, JAC %A Mendes, J %C 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA %D 2004 %I ACADEMIC PRESS INC ELSEVIER SCIENCE %J JOURNAL OF SOLID STATE CHEMISTRY %K Effect; Memory Mossbauer anionic clays; compounds; decomposition; double hydrotalcite-like hydroxides; iron} mixed oxides; pyroaurite; reconstruction; rehydration; spectroscopy; spinel; structural thermal {layered %N 9 %P 3058-3069 %R 10.1016/j.jssc.2004.04.030 %T Thermal decomposition and structural reconstruction effect on Mg-Fe-based hydrotalcite compounds %V 177 %X The thermal decomposition and structural reconstruction of Mg-Fe-based hydrotalcites (FIT) have been studied through thermogravimetric analyses, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy and Mossbauer spectroscopy. The destruction of the layered structure took place at about 300degreesC. The broad peaks observed in the X-ray diffractograms suggest that the resultant oxides constitute a solid solution. For samples treated at temperatures higher than 500degreesC, the formation of the MgO and MgFe2O4 spinel phases is observed. Fe-57 Mossbauer spectroscopy was employed to monitor the Fe chemical environment for the samples annealed at different temperatures (100-900degreesC). In situ XRD experiments revealed that the HTs start an interlayer contraction at about 180degreesC. This phenomenon is identified as being due to a grafting process for which the interlamellar anions attach to the layers through a covalent bond. The reconstruction of the HTs was also investigated and its efficiency depends on the thermal annealing temperature and the Mg/Fe ratio. The structure of the reconstructed samples was found to be exactly the same as the parent structure. (C) 2004 Elsevier Inc. All rights reserved.

@article{WOS:000223960700014, abstract = {The thermal decomposition and structural reconstruction of Mg-Fe-based hydrotalcites (FIT) have been studied through thermogravimetric analyses, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy and Mossbauer spectroscopy. The destruction of the layered structure took place at about 300degreesC. The broad peaks observed in the X-ray diffractograms suggest that the resultant oxides constitute a solid solution. For samples treated at temperatures higher than 500degreesC, the formation of the MgO and MgFe2O4 spinel phases is observed. Fe-57 Mossbauer spectroscopy was employed to monitor the Fe chemical environment for the samples annealed at different temperatures (100-900degreesC). In situ XRD experiments revealed that the HTs start an interlayer contraction at about 180degreesC. This phenomenon is identified as being due to a grafting process for which the interlamellar anions attach to the layers through a covalent bond. The reconstruction of the HTs was also investigated and its efficiency depends on the thermal annealing temperature and the Mg/Fe ratio. The structure of the reconstructed samples was found to be exactly the same as the parent structure. (C) 2004 Elsevier Inc. All rights reserved.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, author = {Ferreira, OP and Alves, OL and Gouveia, DX and Souza, AG and de Paiva, JAC and Mendes, J}, biburl = {https://www.bibsonomy.org/bibtex/2eaf95d02572d5a0bd4c001104a6f973f/ppgfis_ufc_br}, doi = {10.1016/j.jssc.2004.04.030}, interhash = {ef9fddbff47519ccfce545ddf1d2f0e3}, intrahash = {eaf95d02572d5a0bd4c001104a6f973f}, issn = {0022-4596}, journal = {JOURNAL OF SOLID STATE CHEMISTRY}, keywords = {Effect; Memory Mossbauer anionic clays; compounds; decomposition; double hydrotalcite-like hydroxides; iron} mixed oxides; pyroaurite; reconstruction; rehydration; spectroscopy; spinel; structural thermal {layered}, number = 9, pages = {3058-3069}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Thermal decomposition and structural reconstruction effect on Mg-Fe-based hydrotalcite compounds}, tppubtype = {article}, volume = 177, year = 2004 }