Effect of dopants on CeO2 based solid state electrolytes for intermediate temperature electrochemical devices
Ημερομηνία
2011Λέξη-κλειδί
Επιτομή
The present work aims at the investigation of the influence of different dopants' ionic radii and their concentration on both the lattice parameters and the density of Ce1-xLnxO2-δ (x = 0-0.20; Ln = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb) solid solutions, multi-component Ce1-xLnx/2Ln'x/2O2-δ (x = 0-0.20; Ln = Sm, La, Gd and Ln' = Dy, Nd, Y), Ce0.8(Sm 1-xMx)0.2O2-δ (M= Ca, Sr, x=0.0-1.0) and Ce0.8(Sm1-x-yBayM x)0-2O2-δ (M=Ca, Sr, x=0, 0.15, 0.20; y=0.05, 0.1) systems. The electrical conductivity measurements of the samples were carried out by using the four-point dc technique in different atmospheres. Temperature and oxygen partial pressure were varied automatically by means of microprocessor system ZIRKONIA-318 in the range of 623-1173 K and 0.1-10 -23 atm, respectively. To describe the electrolytic properties of solid electrolytes the notation of the EDB (electorytic domain boundary) - the critical oxygen partial pressure (PO2*) at which the values of the electronic and ionic components of conductivity are equal- is often used. The values of the critical partial pressure of oxygen for different compositions at 1023 K were calculated from dependences of total conductivity vs. oxygen partial pressure in proposal that ionic conductivity depends on dopand's concentration, but isn't influenced by PO2.