Artículos de revistas
A comparative study of high temperature properties of cobalt-free perovskites
Fecha
2014-02Registro en:
Basbus, Juan Felipe; Prado, Fernando Daniel; Caneiro, Alberto; Mogni, Liliana Verónica; A comparative study of high temperature properties of cobalt-free perovskites; Springer; Journal Of Electroceramics; 32; 4; 2-2014; 311-318
1385-3449
1573-8663
CONICET Digital
CONICET
Autor
Basbus, Juan Felipe
Prado, Fernando Daniel
Caneiro, Alberto
Mogni, Liliana Verónica
Resumen
Co-free perovskites with chemical composition Ba0.5Sr0.5Fe0.8M0.2O3-δ (M = Ni, Cu, Zn) were synthesized by the modified Pechini method, and their structure and microstructure were characterized by XRD and SEM. Oxygen content, electrical resistivity and Thermal Expansion Coefficient (TEC) were evaluated in air between room temperature and 900 °C. The high-temperature properties of these perovskites were compared with those of Co containing Ba0.5Sr0.5Fe0.8Co0.2O3-δ perovskite. The highest electrical conductivity was obtained for Ba0.5Sr0.5Fe0.8Cu0.2O3-δ, with values of 47.6 Scm−1 at 544 °C. This same composition also exhibits the highest oxygen vacancies concentration: 3-δ = 2.61 at room temperature. In contrast, the Ba0.5Sr0.5Fe0.8Zn0.2O3-δ, showed lower electrical conductivity suggesting that the Zn+2 ions block electron transport. Co-free perovskites seem to be stable at high temperatures for long term periods. However, these compounds suffered degradation at room temperature in samples stored in air.