- Turkish Journal of Chemistry
- Vol: 28 Issue: 5
- Defect Structure and Properties of Sr-Doped La Cr O3-d
Defect Structure and Properties of Sr-Doped La Cr O3-d
Authors : Mahmoud Omari, Ilhem Chadli, Salah Belaidi
Pages : 535-546
View : 11 | Download : 5
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :A defect chemical model for the behavior of acceptor-doped LaCrO3 as a function of oxygen pressure is proposed. This is considered within the regime that corresponds to oxygen deficit oxygen. The mathematical approach allows us to calculate the oxygen partial pressure dependant properties of La1-x Srx Cr O3-d in the range 0.10 \le x \le 0.30. The results show that the conductivity was independent of pO2 and was proportional to the dopant concentration at high pO2. Therefore, under reducing conditions, the conductivity decreased exponentially with decreasing pO2 and asymptotically approached a pO21/4 relationship. Stability regimes and compensation mechanisms at various oxygen partial pressures and temperatures are proposed. This model also examines the charge compensation mechanisms that dominate under the different regimes and their implications for transport properties. From equilibrium constants, thermodynamic quantities such as standard enthalpy and entropy change for the defect formation reactions were calculated.Keywords : Defect modeling, LSC, Perovskite, Nonstoichiometry, Conductivity