On the structural, magnetic and oxygen desorption response of BaxSr1−xFe0.8Co0.2O3−δ (x=0, 0.5 and 1) oxide

Systematic investigation on structure stability and oxygen permeability of Sr-doped BaCo0.7Fe0.2Nb0.1O3−δ ceramic membranes

“…For the BSCFN materials, the tolerance factor is determined by the relative concentrations of the variable Co and Fe species. Thus the tolerance factor should be calculated in three conditions [30]: (a) the Co and Fe are both in quadrivalence; (b) the Co and Fe are both in trivalence; (c) the Co and Fe are in both of bivalence and trivalence. All the involved ionic radii are listed in Table 1 and the calculated tolerance factors are shown in Fig.…”

Effect pH Variation of Powder Materials of the Composite Oxide Ba_(x)Sr_(1-x)Co_(y)Fe_(1-y)O_3-dObtained by Citrate-EDTA Method

“…Bands absorption at approximately 1700 cm -1 are due to symmetric and asymmetric stretching vibrations of the carboxylate functional group in the samples with pH 4.0 and 6.0 (Fig. 5.a) [10]. Two absorption bands were observed at 1436 and 860 cm -1 , after calcination (Fig.…”

“…In this case, the samples present sizes at 240, 778, 778 and 259 Å, for the pH value 2.0, 4.0, 6.0 and 8.0, respectively. In the infrared absorption spectra, the position of the absorption peak is determined by the energy of molecule vibration [10]. FT-IR analysis shows the organic compound present before and after of calcination step, as seen in Fig.…”

Estudo das propriedades do óxido BSCF para aplicação como cátodo em células a combustível de Óxido Sólido de Temperatura Intermediária (ITSOFC)

“…As bandas de absorção, em torno de 1700 cm -1 são correspondentes aos modos vibracionais de estiramento simétrico e assimétrico dos grupos funcionais carboxílicos presentes nas amostras obtidas em pH 4,0 e 6,0. (66,93,108) As , indicando a presença de carbonato estável, devido a decomposição do complexo Ba-EDTA formado na síntese do composto. (66,93,108) Os espectros das amostras de BSCF sem e após calcinação a 900°C apresentam bandas de absorção em números de onda abaixo de 800 cm -1 .…”