Yttrium powder

Solid yttrium metal does not react with oxygen in the air. However, it reacts very rapidly when in its powdered form. Yttrium powder may react explosively with oxygen at high temperatures. 

The results revealed that when yttrium powder was added to the oil-sulfuric lubricant system, the wear of both alloys was greatly reduced. In fact, the wear loss was even smaller than in the plain oil lubricant condition, even though there was no corrosive medium. 

Yttrium—barium—copper oxide, YBa2Cu202 is a newly developed high T material which has been found to be fully superconductive at temperatures above 90 K, a temperature that can be maintained during practical operation. The foremost challenge is to be able to fabricate these materials into a flexible form to prepare wines, fibers, and bulk shapes. Ultrapure powders of yttrium—barium—copper oxide that are sinterable into single-phase superconducting... 

Calorised Coatings The nickel- and cobalt-base superalloys of gas turbine blades, which operate at high temperatures, have been protected by coatings produced by cementation. Without such protection, the presence of sulphur and vanadium from the fuel and chloride from flying over the sea promotes conditions that remove the protective oxides from these superalloys. Pack cementation with powdered aluminium produces nickel or cobalt aluminides on the surfaces of the blade aerofoils. The need for overlay coatings containing yttrium have been necessary in recent times to deal with more aggressive hot corrosion conditions. 

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. 

Boron phases with formulas MB50, and MB,00 (M = Y, Sm, Gd, Tb, Dy, Ho, Er, Yb, Tm, Lu, Th and Pu) are the same cubic phase from x-ray powder data , with the Fm3c Sjpace group. Single crystals of yttrium and thorium borides lead to the formula The MB lattice constant data are given in Table 1. 

Kimura, Y., Ito, T., Yoshikawa, H., Tachiwaki, T., Hiraki, A. Growth and characterization of homogeneous yttrium-barium-copper-oxide (YBa2Cu307-delta) powders prepared by freezedrying method. Jpn. J. Appl. Phys., Part 2, 29 (8), L. 1409 - L 1411, 1990... 

Yttrium (j Y) is often confused with another element of the lanthanide series of rare Earths— Ytterbium ( Yb). Also confusing is the fact that the rare-earth elements terbium and erbium were found in the same minerals in the same quarry in Sweden. Yttrium ranks second in abundance of all 16 rare-earth, and Ytterbium ranks 10th. Yttrium is a dark silvery-gray hghtweight metal that, in the form of powder or shavings, will ignite spontaneously. Therefore, it is considered a moderately active rare-earth metal. 

As a powder or in flne particles, yttrium is flammable and may spontaneously ignite in moist air. Some of its compounds, particularly those used in the semiconductor and electrical industries, are very toxic if inhaled or ingested and should only be used under proper conditions. 

The crystal chemistry of BajRC C has been systematically studied by single-crystal and powder diffraction methods with R = La, Pr,... Yb, in addition to the conventional yttrium compound [(52)(53) (54) and references therein]. With the exception of La, Pr, and Tb, the substitution of Y with rare-earth metals has little or no effect on the superconductivity, with the values of Tc ranging from 87 to 95K. Also, a relatively small change is observed in the cell constants of these compounds. The La, Pr, and Tb-substituted materials are not superconductors. A detailed structural analysis of the Pr case (52) did not show any evidence of a superstructure or the presence of other differences with the atomic configuration of the yttrium prototype. 

Yttrium tri-iTo-propoxide (powder) (1.07 g, 4.0 mmol Kojundo Chemical Laboratory Co., Ltd)... 

The cathodoluminescence of thin films containing rare-earth oxides was studied by Hansen and Myers (140). Films of yttrium oxide doped with rare earths were prepared in vacuum by electron-bombardment evaporation of the oxide powder mixtures. Luminescent rise and decay curves were obtained for activation with europium, gadolinium, terbium, and dysprosium. 

A ternary compound of yttrium with copper and antimony of the stoichiometric ratio 3 3 4 was identified and studied by means of X-ray analysis by Skolozdra et al. (1993). Y3Cu3Sb4 compound was found to have the Y3Au3Sb4 type with the lattice parameter of a = 0.9500 (X-ray powder diffraction). The sample was prepared by melting the metals (around 99.8 wt.% pure for yttrium and 99.99 wt.% for copper and antimony) in an arc furnace and annealing at 870 K for 500 h. 

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