Phase formation and iron oxidation states in SrFe(Al)O3-delta perovskites
authors Waerenborgh, JC; Rojas, DP; Shaula, AL; Mather, GC; Patrakeev, MV; Kharton, VV; Frade, JR
nationality International
journal MATERIALS LETTERS
author keywords perovskite; strontium ferrite-aluminate; Mossbauer spectroscopy; electron-hole conductivity; solid solution range; oxygen nonstoichiometry
keywords MOSSBAUER-SPECTRA; MAGNETIC-PROPERTIES; NONSTOICHIOMETRY; SPECTROSCOPY; VACANCIES; OXIDES
abstract Mossbauer spectroscopy, total conductivity measurements and X-ray diffraction (XRD) have been used to evaluate phase formation and Fe oxidation and coordination states in the Sr(Fe1-xAlx)O3-delta system. A solid-solution range of cubic perovskite (ABO(3)) with random B-cation distribution forms in the approximate limits, 0 <= x <= 0.35. The Fe3+/Fe ratio increases with increasing Al concentration fomenting a B-O network with isolated Fe4+ species, resulting in p-type electronic conductivity via a hopping mechanism. The activation energy for hole transport, 28-30 kJ/mol at 300-700 K in air, exhibits little variation with x. Thermal expansion coefficients, (13.5-16.4)x 10(-6) K-1 at 373-923 K and (18.6-31.9)x 10(-6) K-1 at 923-1273 K, decrease with increasing Al content and oxygen nonstoichiometry. (c) 2005 Elsevier B.V All rights reserved.
publisher ELSEVIER SCIENCE BV
issn 0167-577X
year published 2005
volume 59
issue 13
beginning page 1644
ending page 1648
digital object identifier (doi) 10.1016/j.matlet.2005.01.033
web of science category Materials Science, Multidisciplinary; Physics, Applied
subject category Materials Science; Physics
unique article identifier WOS:000228538900010
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 3.204
5 year journal impact factor 2.785
category normalized journal impact factor percentile 66.536
dimensions (citation analysis):
altmetrics (social interaction):



 


Apoio

1suponsers_list_ciceco.jpg