Erbium

properties
[ Xe ] 4 f 12 6 s 2 68 he Periodic table
General
Name , symbol , atomic number	Erbium, Er, 68
Element category	Lanthanoids
Group , period , block	La , 6 , f
Appearance	silvery white
CAS number	7440-52-0
EC number	231-160-1
ECHA InfoCard	100.028.327
Mass fraction of the earth's envelope	2.3 ppm
Atomic
Atomic mass	167,259 (3) et al
Atomic radius (calculated)	175 (226) pm
Covalent radius	189 pm
Electron configuration	[ Xe ] 4 f 12 6 s 2
1. Ionization energy	6th.1077 (10) eV ≈ 589.3 kJ / mol
2. Ionization energy	11.916 (20) eV ≈ 1 149.7 kJ / mol
3. Ionization energy	22nd.70 (3) eV ≈ 2 190 kJ / mol
4. Ionization energy	42.42 (4) eV ≈ 4 090 kJ / mol
5. Ionization energy	65.1 (4) eV ≈ 6 280 kJ / mol
Physically
Physical state	firmly
Crystal structure	hexagonal
density	9.045 g / cm 3 (25 ° C )
magnetism	paramagnetic ( Χ m = 0.033)
Melting point	1802 K (1529 ° C)
boiling point	3173 K (2900 ° C)
Molar volume	18.46 · 10 −6 m 3 · mol −1
Heat of evaporation	280 kJ / mol
Heat of fusion	19.9 kJ mol −1
Electric conductivity	1.16 · 10 6 A · V −1 · m −1
Thermal conductivity	15 W m −1 K −1
Chemically
Oxidation states	3
Normal potential	−2.32 V (Er 3+ + 3 e - → Er)
Electronegativity	1.24 ( Pauling scale )
Isotopes
isotope NH t 1/2 ZA ZE (M eV ) ZP 162 he 0.14% Stable 163 he {syn.} 75 min ε 1,210 163 Ho 164 he 1.61% Stable 165 he {syn.} 10.36 h ε 0.376 165 Ho 166 he 33.6% Stable 167 he 22.95% Stable 168 he 26.8% Stable 169 he {syn.} 9.40 d β - 0.351 169 Tm 170 he 14.9% Stable
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 167 he +7/2 7.715 · 10 6 2.88
safety instructions
GHS labeling of hazardous substances powder Caution H and P phrases H: 228 P: 210
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Erbium is a chemical element with the element symbol Er and the atomic number 68. In the periodic table it is in the group of lanthanoids and is therefore also one of the rare earth metals . The name is derived from the Ytterby mine near Stockholm , as well as that of ytterbium , terbium and yttrium .

history

Erbium was discovered by Carl Gustav Mosander in 1843 . However, the supposedly pure oxide was a mixture of the oxides from erbium, scandium, holmium, thulium and ytterbium.

The chemists Marc Delafontaine and Nils Johan Berlin made a contribution to the later clarification . The French chemist Georges Urbain and the American chemist Charles James produced pure erbium oxide in 1905 .

Occurrence

Erbium is a rare metal (3.5 ppm ) that does not occur naturally in its pure form, but mainly in the mineral monazite.

Extraction and presentation

After a complex separation of the other erbium companions, the oxide is converted to erbium fluoride with hydrogen fluoride. Subsequently, calcium is used to reduce to metallic erbium with the formation of calcium fluoride . The removal of remaining calcium residues and impurities takes place in an additional remelting process in a vacuum .

properties

Erbium

Physical Properties

The silver-white shiny metal of the rare earths is malleable, but also quite brittle.

Chemical properties

Erbium turns gray in air, but is then quite stable. At higher temperatures it burns to the sesquioxide Er ₂ O ₃ . It reacts with water to form the hydroxide, producing hydrogen. It dissolves in mineral acids with the formation of hydrogen.

In its compounds it is in the +3 oxidation state, the Er ³⁺ cations form pink solutions in water. Solid salts are also colored pink.

use

Erbium-doped optical fibers are used for optical amplifiers that are able to amplify a light signal without converting it into an electrical signal beforehand. Gold as a host material doped with a few hundred ppm erbium is used as a sensor material for magnetic calorimeters for high-resolution particle detection in physics and technology.

Along with other rare earth elements such as neodymium or holmium, erbium is used for doping laser crystals in solid-state lasers (Er: YAG laser, see also Nd: YAG laser ). The Er: YAG laser is mainly used in human medicine. It has a wavelength of 2940 nm and thus an extremely high absorption in tissue water of approx. 12000 per cm.

As a pure beta emitter is ¹⁶⁹ He in nuclear medicine for therapy in the Radiosynoviorthesis used.

Many of its compounds, such as erbium chloride , are colored pink and are therefore used in pottery and glass blowing.

links

• Erbium (III) oxide Er ₂ O ₃
• Erbium (III) fluoride ErF ₃
• Erbium (III) chloride ErCl ₃
• Erbium (III) bromide ErBr ₃
• Erbium (III) iodide ErI ₃
• Erbium (III) sulfate Er ₂ (SO ₄ ) ₃  · 8 H ₂ O: pink crystals
• Erbium (III) nitrate Er (NO ₃ ) ₃  · 5 H ₂ O

Web links

Commons : Erbium  - collection of images, videos and audio files

Wiktionary: Erbium  - explanations of meanings, word origins, synonyms, translations

• Entry to erbium. In: Römpp Online . Georg Thieme Verlag, accessed on January 3, 2015.

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 (Erbium) , unless otherwise stated .
3. ↑ CIAAW, Standard Atomic Weights Revised 2013 .
4. ↑ ^{a b c d e} entry on erbium 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 13, 2020.
5. ↑ ^{a b c d e} entry on erbium at WebElements, https://www.webelements.com , accessed on June 13, 2020.
6. ^ NN Greenwood, A. Earnshaw: Chemistry of the elements. 1st edition. VCH, Weinheim 1988, ISBN 3-527-26169-9 , p. 1579.
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 . 56, 2011, pp. 328-337, doi: 10.1021 / je1011086 .
9. ↑ ^{a b} Entry on erbium, powder in the GESTIS substance database of the IFA , accessed on April 2nd, 2018(JavaScript required) .
10. ↑ The History of the Erbium .
11. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Geophysics, Astronomy, and Acoustics; Abundance of Elements in the Earth's Crust and in the Sea, pp. 14-18.
12. ↑ ^{a b} Gerd Hintermaier-Erhard: Everything is chemistry! The chemical elements and how we use them . Dorling Kindersley Verlag, Munich 2017, ISBN 978-3-8310-3339-3 .
13. ^ German Society for Nuclear Medicine - Guideline of Radiosynoviorthesis .