Electrical and electro-chemical characterisation of La0.99Fe1−xNixO3−δ perovskites

% MathType!Translator!2!1!AMS LaTeX.tdl!TeX -- AMS-LaTeX! % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX % garmWu51MyVXgaruWqVvNCPvMCG4uz3bqec0uyYXwz0rhasaacH8qr % ps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0- % yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqa % ciGacaGaaeqabaWaaeWaeaaakeaacaqGmbGaaeyyamaaBaaaleaaca % qGWaGaaeOlaiaabMdacaqG5aaabeaakiaabAeacaqGLbWaaSbaaSqa % aiaabgdacaqGTaGaaeiEaaqabaGccaqGobGaaeyAamaaBaaaleaaca % qG4baabeaakiaab+eadaWgaaWcbaGaae4maiaab2cacqaH0oazaeqa % aaaa!4260! $$ {\text{La}}_{{{\text{0}}{\text{.99}}}} {\text{Fe}}_{{{\text{1 - x}}}} {\text{Ni}}_{{\text{x}}} {\text{O}}_{{{\text{3 - }}\delta }} $$ (LFN, 0

All the compounds were of single phase, and they belong to either the cubic or the hexagonal crystal system. The thermal expansion coefficient (TEC) was in the range 10.7*10−6 K−1 to 13.4*10−6 K−1, which continued to increase with increasing nickel content. The highest electronic conductivity was measured for the composition % MathType!Translator!2!1!AMS LaTeX.tdl!TeX -- AMS-LaTeX! % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX % garmWu51MyVXgaruWqVvNCPvMCG4uz3bqec0uyYXwz0rhasaacH8qr % ps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0- % yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqa % ciGacaGaaeqabaWaaeWaeaaakeaacaqGmbGaaeyyamaaBaaaleaaca % qGWaGaaeOlaiaabMdacaqG5aaabeaakiaabAeacaqGLbWaaSbaaSqa % aiaabcdacaqGUaGaaeinaaqabaGccaqGobGaaeyAamaaBaaaleaaca % qGWaGaaeOlaiaabAdaaeqaaOGaae4tamaaBaaaleaacaqGZaGaaeyl % aiabes7aKbqabaGccaqGSaaaaa!43F7! $$ {\text{La}}_{{{\text{0}}{\text{.99}}}} {\text{Fe}}_{{{\text{0}}{\text{.4}}}} {\text{Ni}}_{{{\text{0}}{\text{.6}}}} {\text{O}}_{{{\text{3 - }}\delta }} {\text{,}} $$ giving a value of 670 S/cm at 380 °C.

The highest electro-chemical performance was measured for the composition % MathType!Translator!2!1!AMS LaTeX.tdl!TeX -- AMS-LaTeX! % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX % garmWu51MyVXgaruWqVvNCPvMCG4uz3bqec0uyYXwz0rhasaacH8qr % ps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0- % yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqa % ciGacaGaaeqabaWaaeWaeaaakeaacaqGmbGaaeyyamaaBaaaleaaca % qGWaGaaeOlaiaabMdacaqG5aaabeaakiaabAeacaqGLbWaaSbaaSqa % aiaabcdacaqGUaGaaeinaaqabaGccaqGobGaaeyAamaaBaaaleaaca % qGWaGaaeOlaiaabAdaaeqaaOGaae4tamaaBaaaleaacaqGZaGaaeyl % aiabes7aKbqabaaaaa!433E! $$ {\text{La}}_{{{\text{0}}{\text{.99}}}} {\text{Fe}}_{{{\text{0}}{\text{.4}}}} {\text{Ni}}_{{{\text{0}}{\text{.6}}}} {\text{O}}_{{{\text{3 - }}\delta }} $$ giving an area specific resistance as low as 5.5 Ωcm2 at 600 °C based on EIS measurements on a cone-shaped electrode.

Composite cathodes made from % MathType!Translator!2!1!AMS LaTeX.tdl!TeX -- AMS-LaTeX! % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX % garmWu51MyVXgaruWqVvNCPvMCG4uz3bqec0uyYXwz0rhasaacH8qr % ps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0- % yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqa % ciGacaGaaeqabaWaaeWaeaaakeaacaqGmbGaaeyyamaaBaaaleaaca % qGWaGaaeOlaiaabMdacaqG5aaabeaakiaabAeacaqGLbWaaSbaaSqa % aiaabcdacaqGUaGaaeinaaqabaGccaqGobGaaeyAamaaBaaaleaaca % qGWaGaaeOlaiaabAdaaeqaaOGaae4tamaaBaaaleaacaqGZaGaaeyl % aiabes7aKbqabaaaaa!433E! $$ {\text{La}}_{{{\text{0}}{\text{.99}}}} {\text{Fe}}_{{{\text{0}}{\text{.4}}}} {\text{Ni}}_{{{\text{0}}{\text{.6}}}} {\text{O}}_{{{\text{3 - }}\delta }} $$ and CGO10 revealed a rather low performance due to an un-optimised micro-structure.