Author/Authors :
L. Predoana، نويسنده , , B. Malic، نويسنده , , D. Crisan، نويسنده , , N. Dragan، نويسنده , , M. Anastasescu، نويسنده , , J. Calderon-Moreno، نويسنده , , R. Scurtu، نويسنده , , S. Preda and M. Zaharescu، نويسنده ,
Abstract :
The aim of the present study was to establishing the correlation between the structure and properties of the LaCoO3 powders obtained by aqueous sol–gel method with citric acid and their sintering behavior in order to obtain fully densified ceramics with perovskite structure. Two types of cobalt and lanthanum reagents were used in synthesis, namely nitrates and acetates. The sintering was realized at temperatures ranging between 800 and 1200 °C for 2 h. The sintered samples were investigated by classical ceramic methods (shrinkage, density, porosity) and by structural and morphological investigations: XRD, SEM, AFM and XPS. The electrical properties of the samples were determined by impedance spectroscopy. The ceramics obtained with powders starting with acetates have presented a lower sintering ability as compared with the samples obtained from powders starting with nitrates. LaCoO3 ceramics with best properties was obtained from powders starting with nitrates sintered at 1100 °C.
Keywords :
C. Electrical properties , LaCoO3 nano-sized powders , A. Sintering , Aqueous sol–gel method