Yttrium addition

Ren, J.X., Zhou, Z., Gao, X.P., and Yan, J. 2006. Preparation of porous spherical a-Ni(OH)2 and enhancement of high-temperature electrochemical performances through yttrium addition. Electrochimica Acta 52, 1120-1126. 

Yttrium is currently used in the production of plastics as a catalyst for ethylene polymerization, while yttrium additives are used to improve the properties of many ultra-thin films composed of organometallic complexes. 

P. Yu, W. Wang, F. Wang, S. Zhu, High-temperature corrosion behavior of sputtered K38 nanocrystaUine coatings with and without yttrium addition in molten sulfate at 900 °C, Surf Coat. Tech. 206 (2011) 68-74. 

D(cm2/s) = 7.0 x 1010exp[-191(kcal/mol)/RT] in the case of yttrium-doped samples. A comparison of the results suggested that yttrium additions decreased the O grain-boundary diffusivity. 

Liu R, Li D Y (1999) Protective effect of yttrium additive in lubricants on corrosive wear . Wear 225-229, 968-974. 

Zhang TC, Luo Y, Li DY (2000), Erosion behaviour of aluminide coating modified with yttrium addition under different erosion conditions . Surface and Coatings Technology 126,102-109. 

Fig. 20. EfTect of yttrium addition on creep rupture lives of powder metallurgy (PM) and ingot metallurgy (IM)...

The major drawback of the nickel catalyst is poisoning of Ni surface by the interaction with CO to form nickel carbonyl at low temperature. Noble metal based catalysts are more active and stable catalyst in comparison with Ni based catalysts [100]. Among Ru nanoparticle dispersed on various supports (Al Oj, MgAljO, MgO, C, etc ), Ru/Al Oj showed highest catalytic activity (turnover frequency, TOF = 16.5 x 10 s" ) [101,102]. Yttrium addition to the Ru-based catalyst enhances the activity and stability for methanation reaction [103], Pd/Mg-SiO and platinum titanate nanotubes were also foimd... 

Alloys with other useful properties can be obtained by using yttrium as an additive. The metal can be used as a deoxidizer for vanadium and other nonferrous metals. The metal has a low cross section for nuclear capture. 90Y, one of the isotopes of yttrium, exists in equilibrium with its parent 90Sr, a product of nuclear explosions. Yttrium has been considered for use as a nodulizer for producing nodular cast iron, in which the graphite forms compact nodules instead of the usual flakes. Such iron has increased ductility. 

In 1990 world consumption of lanthanides was approximately 35,000 metric tons (45). The most important markets were the United States /Canada (32.8%), China (18.6%), Europe (15.8%), Japan (14.5%), Eastern Europe (9.5%), the rest of Asia (7.3%), and the rest of the world (1.4%). The principal rare-earth manufacturers in 1993 were Molycorp Inc. and RhcJ)ne-Poulenc in the United States RhcJ)ne-Poulenc and Treibacher Chemische WAG in Europe Shinetsu Chemical, Nippon Yttrium, Mitsubishi Chemical Inc., and Santoku Metal Inc. in Japan Indian Rare Earths in India and several additional companies located in the CIS and in the Baotou, Gansu, Yue Long, and Jiangxi provinces in China. 

High Temperature Corrosion. The rate of oxidation of magnesium adoys increases with time and temperature. Additions of berydium, cerium [7440-45-17, lanthanum [7439-91-0] or yttrium as adoying elements reduce the oxidation rate at elevated temperatures. Sulfur dioxide, ammonium fluoroborate [13826-83-0] as wed as sulfur hexafluoride inhibit oxidation at elevated temperatures. 

Yttrium, on the otlrer hand, which has a larger cation radius than Cr +, appears to affect the grain boundary cation diffusion and not the volume diffusion of Ni +. The effects of the addition of small amounts of yttrium to nickel is to decrease dre rate of tire low temperamre grain-boundary dominated oxidation kinetics. 

Other detrimental factors which should to be taken into account in the materials selection process include temperature cycling and the presence of halide gases. Specialist alloys containing rare earth element additions such as cerium, lanthanum and yttrium have been developed for use in certain environments up to 130°C. 

In addition to meeting the foregoing requirements, a good internal standard will be easy to add uniformly and precisely, and (preferably) no appreciable amount of the element St (free or combined) will be present in the sample before the addition. Cope29 provides an excellent illustration of these points. He found that yttrium nitrate dissolved in ethyl alcohol could be added to a powdered uranium mineral in a mortar, whereupon grinding immediately to dryness dispersed the internal standard (yttrium) so uniformly that uranium could be satisfactorily determined in certain minerals. But the mineral euxenite is an exception, for it contains both yttrium and uranium, and this complicates the uranium determination with yttrium as internal standard. 

The lanthanides are congeners of the Group IIIA metals scandium and yttrium, with the +3 oxidation state usually being the most stable. These ions are strong oxyphilic Lewis acids and catalyze carbonyl addition reactions by a number of nucleophiles. Recent years have seen the development of synthetic procedures involving lanthanide metals, especially cerium.195 In the synthetic context, organocerium... 

YIG (yttrium iron garnet), Y3Fe5012, has the same structure as garnet. Which are the appropriate sites for the Y3+ and Fe3+ ions If the electrostatic valence rule is insufficient for you to come to a decision, take ionic radii as an additional criterion. 

Iodine-131 was among the first radioactive isotopes used for radioimmunoconjugate preparation (Order, 1982 Regoeczi, 1984). Since the earliest studies on the efficacy of radiotherapy, additional isotopes have been employed, such as iodine-125, bismuth-212, yttrium-90, yttrium-88, technetium-99 m, copper-67, rhenium-188, rhenium-186, galium-66, galium-67, indium-111, indium-114 m, indium-115, and boron-10. 

In addition to the systems just mentioned, recent kinetic and mechanistic studies have included those involving copper(II) (409,410) and zinc(II) (411) species, various binuclear metal(II) complexes of first row transition elements (412-414), especially iron (407), cobalt (415), copper (305,416), and zinc (417,418), yttrium (419,420) and lanthanide (421,422) species, and thorium(IV) (423). 

---