Rare stabilized zirconia

Rare Earth Stabilized Zirconia Matrix Bricks in The Pilot Test Unit (PTU) at AEDC , Report No AEDC-TR-72-161, Contract F40600-73-C-0004 (Nov 1972) 49) A.D. Kirshenbaum et al,... 

Y-section rayon, 11 262, 263 Ytterbium (Yb), 14 631t, 635t electronic configuration, l 474t Yttria, 5 583, 14 630 Yttria-stabilized zirconia (YSZ), 26 637 Yttric rare earths (RE), 14 631 Yttrium(III)... 

Hydroxyapatite (HAP), with basically the same crystal structure as Ca-deficient, carbonate-containing hydroxyapatite, is compatible with and reactive in a live human body. However, sintered HAP prepared by treating fine HAP particles under elevated temperature and pressure has insufficient mechanical properties, in particular fracture toughness, which greatly limits its commercial applicability. It is rarely implanted alone. On the other hand, zirconia, particularly partially stabilized zirconia (PSZ),... 

The electrical conductivity of rare-earth oxide fluorides was first investigated for the development of a binary anion conductive solid electrolyte. As a result, it was found that the binary rare-earth oxide fluorides exhibited oxide ion conductivity. Among them, the conductivity of neodymium europium oxide fluoride, Nd2Eu203F6, was reported to be much higher than that of yttria-stabilized zirconia, YSZ, practically used as an oxygen sensor [34]. The electrical conductivities of the binary rare-earth oxide fluorides vary not only with the combination of Ln203 with Ln F3... 

Rare-earth fluoride stabilized zirconia, LnFSZ... 

Reaction conditions, compositions and lattice constants of cubic rare-earth fluoride stabilized zirconia... 

Fig. 22. Arrhenius plots of the electrical conductivities of several rare-earth fluoride stabilized zirconias measured under an oxygen partial pressure of 1.33 x 10 1 Pa.

Fig. 23. The transport number of various rare-earth fluoride stabilized zirconias. Oxide ion transport number, tO2 --------- Electron transport number, re-------- ...

The basic elements of a SOFC are (1) a cathode, typically a rare earth transition metal perovskite oxide, where oxygen from air is reduced to oxide ions, which then migrate through a solid electrolyte (2) into the anode, (3) where they combine electrochemically with to produce water if hydrogen is the fuel or water and carbon dioxide if methane is used. Carbon monoxide may also be used as a fuel. The solid electrolyte is typically a yttrium or calcium stabilized zirconia fast oxide ion conductor. However, in order to achieve acceptable anion mobility, the cell must be operated at about 1000 °C. This requirement is the main drawback to SOFCs. The standard anode is a Nickel-Zirconia cermet. 

Yttria and the rare earths find a variety of specialized applications. Y2O3 is used to produce yttria stabilized zirconia ceramics. Cerium, neodynium, and didymium oxides (a... 

Cubic zirconia doped with oxides such as Y203 or CaO is the material of choice for many high temperature applications because of its extremely high ionic conductivity at intermediate and high temperatures. A review on the properties of these specialized rare-earth stabilized zirconia materials has been prepared by Comins et al. [50]. 

The range of the oxygen partial pressure where the rare earth doped ceria exhibits oxide anion conduction is limited over 10" Pa in P02 at 800°C (The oxide anion transference number decreased to 0.5 at this condition.), whereas the well-known stabilized zirconia shows the stable ion conduction between 10" and 10 Pa. This low stability against reducing atmosphere observed in the rare earth doped ceria is a fatal problem for applications. 

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