yttrium

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properties
General
Name , symbol , atomic number Yttrium, Y, 39
Element category Transition metals
Group , period , block 3 , 5 , d
Appearance silvery white
CAS number 7440-65-5
EC number 231-174-8
ECHA InfoCard 100.028.340
Mass fraction of the earth's envelope 26 ppm
Atomic
Atomic mass 88.90584 (2) and
Atomic radius (calculated) 180 (212) pm
Covalent radius 190 pm
Electron configuration [ Kr ] 4 d 1 5 s 2
1. Ionization energy 6th.21726 (10) eV ≈ 599.87 kJ / mol
2. Ionization energy 12.2236 (6) eV ≈ 1 179.4 kJ / mol
3. Ionization energy 20th.52441 (12) eV ≈ 1 980.3 kJ / mol
4. Ionization energy 60.6072 (25) eV ≈ 5 847.7 kJ / mol
5. Ionization energy 75.35 (4) eV ≈ 7 270 kJ / mol
Physically
Physical state firmly
Crystal structure hexagonal
density 4.472 g / cm 3
magnetism paramagnetic ( Χ m = 1.2 · 10 −4 )
Melting point 1799 K (1526 ° C)
boiling point 3203 K (2930 ° C)
Molar volume 19.88 10 −6 m 3 mol −1
Heat of evaporation 390 kJ / mol
Heat of fusion 11.4 kJ mol −1
Speed ​​of sound 3300 m s −1 at 293.15 K.
Electric conductivity 1.66 · 10 6 A · V −1 · m −1
Thermal conductivity 17 W m −1 K −1
Chemically
Oxidation states +3
Normal potential −2.37 V (Y 3+ + 3 e - → Y)
Electronegativity 1.22 ( Pauling scale )
Isotopes
isotope NH t 1/2 ZA ZE (M eV ) ZP
86 Y {syn.} 14.7 h β + 534 86 Sr
87 Y {syn.} 79.8 h ε 1,862 87 Sr
88 Y {syn.} 106.65 d ε 3.623 88 Sr
89 Y 100  % Stable
90 Y {syn.} 64.10 h β - 2.282 90 Zr
91 Y {syn.} 58.51 d β - 1.544 91 Zr
For other isotopes see list of isotopes
NMR properties
  Spin
quantum
number I 		γ in
rad · T −1 · s −1 		E r  ( 1 H) f L at
B = 4.7 T
in MHz
89 Y 1/2 −1.316 10 7 0.000119 4.9
safety instructions
GHS labeling of hazardous substances

powder

02 - Highly / extremely flammable

danger

H and P phrases H: 228
P: 210-241-280-241-370 + 378
As far as possible and customary, SI units are used.
Unless otherwise noted, the data given apply to standard conditions .

Yttrium [ ˈʏtri̯ʊm ] is a chemical element with the element symbol Y and the atomic number 39. It is one of the transition metals and the rare earth metals , in the periodic table it is in the 5th period and the 3rd subgroup , or the 3rd  IUPAC group or Scandium group . Yttrium is named after its first location, the Ytterby mine near Stockholm , as are ytterbium , terbium and erbium .

history

Yttrium was discovered in 1794 by Johan Gadolin in the mineral ytterbit . In 1824 Friedrich Wöhler produced contaminated yttrium by reducing yttrium chloride with potassium. It was not until 1842 that Carl Gustav Mosander succeeded in separating the yttrium from the accompanying elements erbium and terbium .

Occurrence

Yttrium does not occur naturally in its elemental state. Yttrium-containing minerals (ytter earths) are always related to other rare earth metals. It can also be found in uranium ores. Monazite sands , which contain up to 3% yttrium, and bastnasite , which contains 0.2% yttrium, are commercially viable . It is also the main component of xenotime (Y [PO 4 ]).

Large deposits of monazite, discovered and exploited in Brazil and India in the early 19th century, made these two countries major producers of yttrium ores. It was not until the opening of the Mountain Pass Mine in California, which produced large amounts of bastnesite until the 1990s, that the USA became the main producer of yttrium, even though the bastnesite mined there contains only a small amount of yttrium. Since this mine was closed, China has been the largest producer of rare earths with 60%. These are extracted in a mine near Bayan Kuang , the ore of which contains xenotime, and from ion-absorbing clay minerals , which are mainly mined in southern China.

Extraction and presentation

The separation of the rare earths from one another is a complex step in the production of yttrium. Fractional crystallization of salt solutions was the preferred method in the beginning, this was used early on for the separation of the rare earths on a laboratory scale. Only the introduction of ion chromatography made it possible to separate rare earths on an industrial scale.

The concentrated yttrium oxide is converted into fluoride . The subsequent reduction to metal takes place with calcium in a vacuum induction furnace .

The USGS estimated the annual production for 2014 at 7,000 t of yttrium oxide (Y 2 O 3 ) and the consumption at 6,000 t. The production took place almost exclusively in China. The price of yttria with a purity of 99.999% rose from US $ 25-27 per kg in 2010 to US $ 136-141 in 2011 and fell again to US $ 23-27 by 2013. In August 2015 the price was around USD 5.5 per kg.

properties

Yttrium, sublimed in a high vacuum, highly pure

Yttrium is relatively stable in air , but darkens under light. Fresh interfaces can ignite at temperatures above 400 ° C. Finely divided yttrium is relatively unstable. Yttrium has a low capture cross section for neutrons .

It is mostly trivalent in its compounds. However, there are also cluster compounds in which yttrium can assume oxidation states below 3. Yttrium is one of the light metals .

Isotopes

A total of 32 isotopes between 76 Y and 108 Y and a further 24 core isomers are known. Of these, only 89 Y, which is also exclusively made up of natural yttrium, is stable. So yttrium is one of 22 pure elements . The most stable radioisotopes are 88 Y with a half-life of 106.65 days and 91 Y with a half-life of 58.51 days. All other isotopes have a half-life of less than a day, with the exception of 87 Y, which has a half-life of 79.8 hours, and 90 Y, which is 64 hours. Yttrium isotopes are one of the most common products of the fission of uranium in nuclear reactors and in nuclear explosions.

→ List of yttrium isotopes

use

Metallic yttrium is used in reactor technology for tubes. The alloy with cobalt YCo 5 can be used as a rare earth magnet . Yttrium is used as a material for heating wires in ion sources in mass spectrometers . In metallurgy , small amounts of yttrium are used for grain refinement , for example in iron-chromium-aluminum heating conductor alloys , chromium, molybdenum, titanium and zirconium alloys . In aluminum and magnesium alloys, it increases the strength. Doping lithium iron phosphate batteries with yttrium increases their performance and durability.

Technically more important are the oxidic yttrium compounds:

The most important use of yttrium oxides and yttrium oxide sulfides, however, is the wide range of possible uses in trivalent europium (red) and thulium (blue) doped luminophores (fluorescent substances ) in television picture tubes and fluorescent lamps .

Yttrium ceramics and alloys are also used in:

As a pure beta emitter , 90 Y is used for therapy in nuclear medicine , for example for radiosynoviorthesis , radionuclide therapy for bone metastases , radioimmunotherapy and for colorectal carcinoma .

Biology and toxicity

Yttrium is not considered an essential trace element. The toxic properties of the metallic yttrium do not lead to a classification as a hazardous substance. An occupational exposure limit for yttrium is not specified. The Occupational Safety and Health Administration (OSHA) recommends a MAK value of 1 mg / m 3 for an exposure period of 8 hours.

links

Web links

Commons : Yttrium  - album with pictures, videos and audio files
Wiktionary: Yttrium  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ Harry H. Binder: Lexicon of the chemical elements. S. Hirzel Verlag, Stuttgart 1999, ISBN 3-7776-0736-3 .
  2. ↑ The values ​​for the properties (info box) are taken from www.webelements.com (Yttrium) , unless otherwise stated .
  3. ^ IUPAC, Standard Atomic Weights Revised v2 ( Memento of March 3, 2016 in the Internet Archive ).
  4. ↑ CIAAW, Standard Atomic Weights Revised 2013 .
  5. ↑ a b c d e Entry on yttrium in Kramida, A., Ralchenko, Yu., Reader, J. and NIST ASD Team (2019): NIST Atomic Spectra Database (ver. 5.7.1) . Ed .: NIST , Gaithersburg, MD. doi : 10.18434 / T4W30F ( https://physics.nist.gov/asd ). Retrieved June 11, 2020.
  6. ↑ a b c d e Entry on yttrium at WebElements, https://www.webelements.com , accessed on June 11, 2020.
  7. ↑ Robert C. Weast (Ed.): CRC Handbook of Chemistry and Physics . CRC (Chemical Rubber Publishing Company), Boca Raton 1990, ISBN 0-8493-0470-9 , pp. E-129 to E-145. Values ​​there are based on g / mol and given in cgs units. The value specified here is the SI value calculated from it, without a unit of measure.
  8. ↑ a b Yiming Zhang, Julian RG Evans, Shoufeng Yang: Corrected Values ​​for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks. In: Journal of Chemical & Engineering Data . Volume 56, 2011, pp. 328-337, doi: 10.1021 / je1011086 .
  9. ↑ a b c Entry on yttrium in the GESTIS substance database of the IFA , accessed on April 30, 2017(JavaScript required) .
  10. ↑ MINERAL COMMODITY SUMMARIES 2015. (PDF 2.3 MB, pp. 185–186 (182–183)) USGS , accessed on September 6, 2015 (English).
  11. ↑ Japanese yttrium oxide price keeps steady. www.asianmetal.com, September 6, 2015, accessed September 6, 2015 (English).
  12. ↑ G. Audi, O. Bersillon, J. Blachot, AH Wapstra: The NUBASE evaluation of nuclear and decay properties ( Memento of February 24, 2014 in the Internet Archive ). (PDF; 1.0 MB). In: Nuclear Physics. Vol. A 729, 2003, pp. 3–128.
  13. ^ E. Janowski, O. Timofeeva, S. Chasovskikh, M. Goldberg, A. Kim, F. Banovac, D. Pang, A. Dritschilo, K. Unger: Yttrium-90 radioembolization for colorectal cancer liver metastases in KRAS wild- type and mutant patients: Clinical and ccfDNA studies. In: Oncol Rep. Volume 37, No. 1, Jan 2017, pp. 57-65. PMID 28004119
  14. ↑ Yttrium . In: Occupational Safety and Health Administration (Ed.): Permissible Exposure Limits . Annotated Table Z-1. ( osha.gov [accessed March 11, 2019]).