yttrium


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yttrium

(ĭt`rēəm) [for Ytterby, a town in Sweden], metallic chemical element; symbol Y; at. no. 39; at. wt. 88.90585; m.p. about 1,522°C;; b.p. 3,338°C;; sp. gr. about 4.45; valence +3. Yttrium is a highly crystalline iron-gray metal. Usually considered a rare-earth metalrare-earth metals,
in chemistry, group of metals including those of the lanthanide series and actinide series and usually yttrium, sometimes scandium and thorium, and rarely zirconium. Promethium, which is not found in nature, is not usually considered a rare-earth metal.
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, it is found above lanthanum in Group 3 of the periodic tableperiodic table,
chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled
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. Yttrium is fairly stable in air but oxidizes readily when heated. It reacts with water and mineral acids. The largest use of the element is as its oxide yttria, Y2O3, which is used in making red phosphors for color television picture tubes; it also has other uses. Yttrium metal has found some use alloyed in small amounts with other metals. Yttrium is not found uncombined in nature, but occurs in many minerals, e.g., gadolinite, euxenite, and xenotime. It is recovered commercially from monazite and bastnasite. In 1794, Johan Gadolin isolated impure yttria from the mineral gadolinite. In 1843, C. G. Mosander isolated pure yttria as well as two impure fractions that he called erbia and terbia. The metal was first isolated in 1828 by Friedrich Wöhler.

Yttrium

 

a chemical element in Group III of the Mendeleev periodic system. Atomic number, 39; atomic weight, 88.9059. One stable isotope, 89Y, exists in nature.

Yttrium, scandium, lanthanum, and lanthanides make up the rare earths, a group of elements that are very similar in chemical properties, occurrence in nature, and history of discovery.

Yttrium is a light metal, with a density of 4.472 g/cm3. Theisotope 89Y has a small capture cross section for thermal neu-trons (1.38 ×a 10-28m2, or 1.38 barns), so that the element can be used as a construction material in nuclear engineering. The high durability of relatively light yttrium-aluminum alloys makes them highly suitable for aircraft construction. Yttrium ferrites can be prepared from yttrium oxide, Y2003 (of very highpurity); these ferrites are used in radio electronics, hearing aids, and computer memory cells.

yttrium

[′i·trē·əm]
(chemistry)
A rare-earth metal, symbol Y, atomic number 39, atomic weight 88.9059; dark-gray, flammable (as powder), soluble in dilute acids and potassium hydroxide solution, and decomposes in water; melts at 1500°C, boils at 2927°C; used in alloys and nuclear technology and as a metal deoxidizer.

yttrium

a silvery metallic element occurring in monazite and gadolinite and used in various alloys, in lasers, and as a catalyst. Symbol: Y; atomic no.: 39; atomic wt.: 88.90585; valency: 3; relative density: 4.469; melting pt.: 1522?C; boiling pt.: 3338?C
References in periodicals archive ?
Mehrzadi et al., "Neuro-protective effects of cerium and yttrium oxide nanoparticles on high glucose-induced oxidative stress and apoptosis in undifferentiated PC12 cells," Neurological Research, vol.
Rare earth elements and Yttrium in carbonate reef deposits containing hydrocarbons of oil and gas.
The XRD patterns of both undoped and yttrium doped ZnS showed three main diffraction peaks indexed at (111), (220), and (311) which correspond to the planes of cubic zinc blende structure, respectively.
Jaffe, "The role of yttrium and other minor elements in the garnet group," American Mineralogist, vol.
Yttrium has many high-tech and defence uses including being used an alloy for exotic light-weight jet engine turbines and other parts.
The experiments showed that yttrium in trace amounts - less than 1 microgram per milliliter of water - may disrupt normal calcium signalling in neurons and other electrically active cells, an amount far lower than what had been thought to be safe levels.
In the past, tunable band-stop filters have used dielectric ferromagnets such as Yttrium Iron Garnet (YIG).
Bokan Mountain, Alaska's only known source of uranium, is rich in niobium, yttrium, thorium, zirconium and hafnium.
Argon lasers can also lower pressure inside the eye to treat open-angle glaucoma, while YAG (Yttrium Aluminum Garnet) lasers (photodisruptive lasers) can create a new drainage system in narrow-angle glaucoma or can remove membranes after cataract surgery.
In the next few years, he isolated four other elements from the rare earth minerals: yttrium, erbium, terbium, and didymium.
installation of laser welding sisma lm-d 100 , or similar machine dimensions: 540 x 690 x 460 mm (width x length x height) machine weight: 55 kg laser source type: nd: yag (neodymium: yttrium aluminum ) laser source hazard class: 4 wavelength: 1064 nm max.