Determination of the Mn3+/Mn4+ ratio in La1−xSrxMnO3±d powders

Siqueira, Guilherme Oliveira; Belardi, Rose Marie; Almeida, Pedro Hespanha; Silva, Charles Luís da; Brant, Márcia Caldeira; Matencio, Túlio; Domingues, Rosana Zacarias

doi:10.1016/j.jallcom.2012.01.023

Cited by 8 publications

(2 citation statements)

References 44 publications

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“…Several doped and mixed oxides have been proposed as cathode but lanthanum strontium manganite (LSM) has been considered the most promising material for high temperature applications. This is due to its high electronic conductivity, chemical stability, thermal compatibility with the electrolyte (yttrium stabilized zirconia, YSZ) and high catalytic activity for oxygen reduction [7,13].…”

Section: Introductionmentioning

confidence: 99%

Effect of La 0.8 Sr 0.2 MnO 3 powder addition in the precursor solution on the properties of cathode films deposited by spray pyrolysis

Silva¹,

Gama²,

Santos

et al. 2017

Matéria (Rio J.)

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Films of lanthanum strontium manganite, LSM (La 0.8 Sr 0.2 MnO 3 ) were deposited on yttria stabilized zirconia (YSZ) substrates by different methods aiming to establish the most suitable route to prepare cathodes for solid oxide fuel cells (SOFC). Samples were obtained by using a solution of lanthanum, strontium and manganese nitrates or a dispersion of the LSM powder in this solution. Both commercial and synthetized LSM powders were used, the last one obtained by amorphous citrate method. The films were deposited by spray pyrolysis on YSZ substrates prepared by uniaxial and isostatic pressing. Samples were characterized by scanning electron microscopy, confocal laser scanning microscopy, X-ray diffraction and two-probe conductivity measurements. The area specific resistance and relaxation to cathodic activation were measured by electrochemical impedance spectroscopy. The substrate obtained by uniaxial pressing and the commercial LSM produced films with the highest amount of surface cracks. The film obtained from the suspension showed area specific resistance and activation energy lower than the other produced from the solution. For both samples, the cathodic activation process resulted in an initial reduction of the total resistance of around 20%, the sample produced from the suspension being more resistant to relaxation. Therefore, the LSM suspension is more suitable than the salts solution for preparing films by spray pyrolysis on YSZ substrates to obtain efficient cathodes for SOFC.

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Section: Introductionmentioning

confidence: 99%

Effect of La 0.8 Sr 0.2 MnO 3 powder addition in the precursor solution on the properties of cathode films deposited by spray pyrolysis

Silva¹,

Gama²,

Santos

et al. 2017

Matéria (Rio J.)

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show abstract

“…The changing Mn 3+ /Mn 4+ ratios in the CMR materials are essentially related to the doping mechanism to control the effective Mn valency [9,10]. This is achieved by either substitution and/or by changing overall oxygen contents, which determines the value of metal to semiconducting transition temperature, T P .…”

Section: Introductionmentioning

confidence: 99%