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Temperature-independent sensors based on perovskite-type oxides

TitoloTemperature-independent sensors based on perovskite-type oxides
Tipo di pubblicazionePresentazione a Congresso
Anno di Pubblicazione2014
AutoriZaza, F., Frangini S., Leoncini J., Luisetto I., Masci A., Pasquali M., and Tuti S.
Conference NameAIP Conference Proceedings
EditoreAmerican Institute of Physics Inc.
Conference LocationRome
ISBN Number9780735412378
Parole chiaveAluminum, Chemical elements, Combustion synthesis, Combustion synthesis method, Electrical measurement, Internal combustion engines, Iron oxides, Lanthanum, Lanthanum Strontium ferrite, Large specific surface areas, Lean combustion, Materials properties, Nanostructured materials, Oxygen, Oxygen sensing materials, Oxygen sensors, Perovskite, Perovskite oxides, Perovskite type oxides, Sustainable development
Abstract

The need of energy security and environment sustainability drives toward the development of energy technology in order to enhance the performance of internal combustion engines. Gas sensors play a key role for controlling the fuel oxygen ratio and monitoring the pollution emissions. The perovskite-type oxides can be synthesized for an extremely wide variety of combinations of chemical elements, allowing to design materials with suitable properties for sensing application. Lanthanum strontium ferrites, such as La 0.7Sr0.3FeO3, are suitable oxygen sensing materials with temperature-independence conductivity, but they have low chemical stability under reducing conditions. The addition of aluminum into the perovskite structure improves the material properties in order to develop suitable oxygen sensing probes for lean burn engine control systems. Perovskite-type oxides with formula (La0.7Sr0.3FeO 3,)(AlxFe1-x)O3 was synthesized by the citrate-nitrate combustion synthesis method. XRD analyses, show that it was synthesized a phase-pure powder belonging to the perovskite structure. Aluminum affects both the unit cell parameters, by shrinking the unit cell, and the powder morphology, by promoting the synthesis of particles with small crystallite size and large specific surface area. The partial substitution of iron with aluminum improves the chemical stability under reducing gas conditions and modulates the oxygen sensitivity by affecting the relative amount of Fe4+ and Fe3+, as confirmed from TPR profiles. In the same time, the addition of aluminum does not affects the temperature-independent properties of lanthanum strontium ferrites. Indeed, the electrical measurements show that (La0.7Sr0.3)(AlxFe1-x)O3 perovskites have temperature-independence conductivity from 900 K. © 2014 AIP Publishing LLC.

URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-84904013090&doi=10.1063%2f1.4883042&partnerID=40&md5=7727f3076df644a67fe0198390b98c56
DOI10.1063/1.4883042
Citation KeyZaza201453