کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1332111 | 979030 | 2006 | 6 صفحه PDF | دانلود رایگان |
We have employed aliovalent A-site cation substitution, LaIII-for-SrII, to dope the Sr(Fe0.5Ta0.5)O3 perovskite oxide with electrons. Essentially single-phase samples of (Sr1−xLax)(Fe0.5Ta0.5)O3 were successfully synthesized up to x≈0.3 in a vacuum furnace at 1400 °C. The samples were found to crystallize (rather than with orthorhombic symmetry) in monoclinic space group P21/n that accounts for the partial ordering of the B-site cations, Fe and Ta. With increasing La-substitution level, x, the degree of Fe/Ta order was found to increase such that the La-richest compositions are best described by the B-site ordered double-perovskite formula, (Sr,La)2FeTaO6. From Fe L3 and Ta L3 XANES spectra it was revealed that upon electron doping the two B-site cations, FeIII and TaV, are both prone to reduction. Magnetic susceptibility measurements showed spin-glass type behaviour for all the samples with a transition temperature slightly increasing with increasing x.
Valence states of Fe and Ta are controlled in the partially ordered perovskite oxide, (Sr,La)2FeTaO6, through aliovalent LaIII-for-SrII substitution.Figure optionsDownload as PowerPoint slide
Journal: Journal of Solid State Chemistry - Volume 179, Issue 1, January 2006, Pages 111–116