Ceria-yttria

Hidenori, Y. et al.. High temperature fuel cell with ceria-yttria solid electrolyte, J. Electrochem. Soc. Solid-State Sci. Technol., 2077-2080 (1988). 

Tlie CVD method is usually used to produce a thin film material which is formed on a heated substrate. However, nanostructured particles of ceria and ceria-yttria have been synthesized by some arrangements of the apparatus. Figure 3.8 shows the schematic CVD reactors for synthesizing ceria-based nanopanicles.Two types of rector has been presented. The nanoparticles are collected either on a cooled quartz susceptor (A) that is in a furnace, or in a cold wall container outside the furnace (B), The precursor cerium chloride set on the container is evaporated and... 

Sanna, S., Esposito, V., Tebano, A., Licoccia, S., Traversa, E., and Balestrino, G. (2010) Enhancement of ionic conductivity in Sm-doped ceria/yttria-stabilized zirconia heteroepitaxial structures. Small, 6, 1863-1867. 

Visualization of diffusion pathway of oxide ions in the ceria-yttria solid solution Cei fVJ)2 x/2... 

Recent precise structural analyses of ceria-zirconia and ceria-rare-earth-oxides have demonstrated the positional disorder and diffusional pathway of oxide ions at high temperatures. In a ceria-yttria material, the oxide ions diffuse along the <100> directions (Fig. 1. 32). We found that the diffusion coefficient increases with... 

H. Mitsuyasu, Y. Nonaka, K. Eguchi, Analysis on Solid State Reaction at the Interface of Yttria-Doped Ceria/Yttria-Stabilized Zirconia, Solid State Ionics 113-115,279-284 (1998) N. Sakai, H. Kishimoto, K. Yamaji, T. Horita, M.E. Brito, H. Yokokawa, Degradation Behavior at Interface of LSCF Cathodes and Rare Earth Doped Ceria, SOFC X, ECS Transactions, 7(1) 389-398 (2007)... 

S. Sanna, V. Esposito, A. Tebano, S. Licoccia, E. Traversa, G. Balestrino, Enhancement of ionic conductivity in Sm-Doped Ceria/Yttria-stabilized Zirconia Heteroepitaxial Stmctures. Small 6, 1863-1867 (2010)... 

In 1751 the Swedish mineralogist, A. F. Cronstedt, discovered a heavy mineral from which in 1803 M. H. Klaproth in Germany and, independently, i. i. Berzelius and W. Hisinger in Sweden, isolated what was thought to be a new oxide (or earth ) which was named ceria after the recently discovered asteroid, Ceres. Between 1839 and 1843 this earth, and the previously isolated yttria (p. 944), were shown by the Swedish surgeon C. G. Mosander to be mixtures from which, by 1907, the oxides of Sc, Y, La and the thirteen lanthanides other than Pm were to be isolated. The small village of Ytterby near Stockholm is celebrated in the names of no less than four of these elements (Table 30.1). 

Other refractory oxides that can be deposited by CVD have excellent thermal stability and oxidation resistance. Some, like alumina and yttria, are also good barriers to oxygen diffusion providing that they are free of pores and cracks. Many however are not, such as zirconia, hafnia, thoria, and ceria. These oxides have a fluorite structure, which is a simple open cubic structure and is particularly susceptible to oxygen diffusion through ionic conductivity. The diffusion rate of oxygen in these materials can be considerable. 

FIGURE 1.2 Composition dependence of conductivity for yttria-stabilized zirconia (YSZ) measured at 1000°C [7], yttria-doped bismuth oxide (YDB) at 600°C [6], and yttria-doped ceria (YDC) at 700°C [8],... 

Figure 46. Performance characteristics of a cathode-supported thin film Ni—YSZ/YSZ/LSM fuel cell at 600 °C in humidified H2 and air with and without a dense protective yttria-doped ceria (YDC) protection layer introduced between the porous LSM cathode and the thin-film electrolyte. (Reprinted with permission from ref 296. Copyright 1997 Elsevier.)...

Cerium was the first rare-earth element discovered, and its discovery came in 1803 by Jons Jakob Berzelius in Vienna. Johann Gadohn (1760—1852) also studied some minerals that were different from others known at that time. Because they were different from the common earth elements but were all very similar to each other, he named them rare-earth elements. However, he was unable to separate or identify them. In the 1800s only two rare-earths were known. At that time, they were known as yttria and ceria. Carl Gustav Mosander (1797—1858) and several other scientists attempted to separate the impurities in these two elements. In 1839 Mosander treated cerium nitrate with dilute nitric acid, which yielded a new rare-earth oxide he called lanthanum. Mosander is credited with its discovery. This caused a change in the periodic table because the separation produced two new elements. Mosander s method for separating rare-earths from a common mineral or from each other led other chemists to use... 

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