Publication result detail
Synthesis, structure and oxygen thermally programmed desorption spectra of La1-xCaxAlyFe1-yO3-d perovskites
CIHLÁŘ, J.; DEL FAVERO, D.; CIHLÁŘ, J.; BUCHAL, A.; VAN HERLE, J.
Original Title
Synthesis, structure and oxygen thermally programmed desorption spectra of La1-xCaxAlyFe1-yO3-d perovskites
English Title
Synthesis, structure and oxygen thermally programmed desorption spectra of La1-xCaxAlyFe1-yO3-d perovskites
Type
Peer-reviewed article not indexed in WoS or Scopus
Original Abstract
Perovskites La1-xCaxAlyFe1-yO3-d (x, y = 0 to 1) were prepared by high-temperature solid-state synthesis based on mixtures of oxides produced by colloidal milling. The XRD analysis showed that perovskites La0.5Ca0.5AlyFe1-yO3-d with a high Fe content (1 - y = 0.8-1.0) were of orthorhombic structure, perovskites with a medium Fe content (1 - y = 0.8-0.5) were of rhombohedral structure, and perovskite with the lowest Fe content (1 - y = 0.2) were of cubic structure. Thermally programmed desorption (TPD) of oxygen revealed that chemical desorption of oxygen in the temperature range from 200 to 1000 degC had proceeded in the two desorption peaks. The low-temperature alfa-peak (in the 200-550 degC temperature range) was brought about by oxygen liberated from oxygen vacancies; the high-temperature beta-peak (in the 550-1000 degC temperature range) corresponded to the reduction of Fe4+ to Fe3+. The chemidesorption oxygen capacity increased with increasing Ca content and decreased with increasing Al content in the perovskites. The Al3+ ions restricted, probably for kinetic reasons, the reduction of Fe4+ and the high-temperature oxygen desorption associated with it.
English abstract
Perovskites La1-xCaxAlyFe1-yO3-d (x, y = 0 to 1) were prepared by high-temperature solid-state synthesis based on mixtures of oxides produced by colloidal milling. The XRD analysis showed that perovskites La0.5Ca0.5AlyFe1-yO3-d with a high Fe content (1 - y = 0.8-1.0) were of orthorhombic structure, perovskites with a medium Fe content (1 - y = 0.8-0.5) were of rhombohedral structure, and perovskite with the lowest Fe content (1 - y = 0.2) were of cubic structure. Thermally programmed desorption (TPD) of oxygen revealed that chemical desorption of oxygen in the temperature range from 200 to 1000 degC had proceeded in the two desorption peaks. The low-temperature alfa-peak (in the 200-550 degC temperature range) was brought about by oxygen liberated from oxygen vacancies; the high-temperature beta-peak (in the 550-1000 degC temperature range) corresponded to the reduction of Fe4+ to Fe3+. The chemidesorption oxygen capacity increased with increasing Ca content and decreased with increasing Al content in the perovskites. The Al3+ ions restricted, probably for kinetic reasons, the reduction of Fe4+ and the high-temperature oxygen desorption associated with it.
Key words in English
Perovskites; membranes; X-ray methods; powders-solid state reaction; chemisorption
Authors
CIHLÁŘ, J.; DEL FAVERO, D.; CIHLÁŘ, J.; BUCHAL, A.; VAN HERLE, J.
Released
01.01.2006
Publisher
Elsevier Science
ISBN
0955-2219
Periodical
Journal of the European Ceramic Society
Volume
26
Number
14
State
United Kingdom of Great Britain and Northern Ireland
Pages from
2999
Pages to
3004
Pages count
6
URL
BibTex
@article{BUT43557,
author="Jaroslav {Cihlář} and David {Del Favero} and Jaroslav {Cihlář} and Antonín {Buchal} and Jan {Van herle}",
title="Synthesis, structure and oxygen thermally programmed desorption spectra of La1-xCaxAlyFe1-yO3-d perovskites",
journal="Journal of the European Ceramic Society",
year="2006",
volume="26",
number="14",
pages="2999--3004",
issn="0955-2219",
url="http://www.sciencedirect.com"
}