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Erbium

2007 Schools Wikipedia Selection. Related subjects: Chemical elements


                68               holmium ← erbium → thulium
                 -
                ↑
                Er
                ↓
                Fm

                                  Periodic Table - Extended Periodic Table

                                                                   General
                                       Name, Symbol, Number erbium, Er, 68
                                               Chemical series lanthanides
                                            Group, Period, Block n/a, 6, f
                                                  Appearance silvery white
                                             Atomic mass 167.259 (3) g/mol
                                    Electron configuration [Xe] 4f^12 6s^2
                                    Electrons per shell 2, 8, 18, 30, 8, 2
                                                       Physical properties
                                                               Phase solid
                                      Density (near r.t.) 9.066 g·cm^−3
                                    Liquid density at m.p. 8.86 g·cm^−3
                                                     Melting point 1802  K
                                                    (1529 ° C, 2784 ° F)
                                                      Boiling point 3141 K
                                                    (2868 ° C, 5194 ° F)
                                         Heat of fusion 19.90 kJ·mol^−1
                                     Heat of vaporization 280 kJ·mol^−1
                          Heat capacity (25 °C) 28.12 J·mol^−1·K^−1

   CAPTION: Vapor pressure

                               P/Pa   1    10   100    1 k    10 k  100 k
                              at T/K 1504 1663 (1885) (2163) (2552) (3132)

                                                         Atomic properties
                                               Crystal structure hexagonal
                                                        Oxidation states 3
                                                            ( basic oxide)
                                    Electronegativity 1.24 (Pauling scale)
                                                       Ionization energies
                                           ( more) 1st: 589.3 kJ·mol^−1
                                                    2nd: 1150 kJ·mol^−1
                                                    3rd: 2194 kJ·mol^−1
                                                      Atomic radius 175 pm
                                              Atomic radius (calc.) 226 pm
                                                             Miscellaneous
                                                 Magnetic ordering no data
                       Electrical resistivity ( r.t.) (poly) 0.860 µΩ·m
                       Thermal conductivity (300 K) 14.5 W·m^−1·K^−1
                                          Thermal expansion ( r.t.) (poly)
                                                           12.2 µm/(m·K)
                               Speed of sound (thin rod) (20 °C) 2830 m/s
                                                  Young's modulus 69.9 GPa
                                                    Shear modulus 28.3 GPa
                                                     Bulk modulus 44.4 GPa
                                                       Poisson ratio 0.237
                                                  Vickers hardness 589 MPa
                                                  Brinell hardness 814 MPa
                                             CAS registry number 7440-52-0
                                                         Selected isotopes

                  CAPTION: Main article: Isotopes of erbium

                               iso     NA   half-life DM  DE ( MeV)   DP
                              ^160Er syn    28.58 h   ε   0.330     ^160Ho
                              ^162Er 0.14%  Er is stable with 94 neutrons
                              ^164Er 1.61%  Er is stable with 96 neutrons
                              ^165Er syn    10.36 h   ε   0.376     ^165Ho
                              ^166Er 33.6%  Er is stable with 98 neutrons
                              ^167Er 22.95% Er is stable with 99 neutrons
                              ^168Er 26.8%  Er is stable with 100 neutrons
                              ^169Er syn    9.4 d     β^- 0.351     ^169Tm
                              ^170Er 14.9%  Er is stable with 102 neutrons
                              ^171Er syn    7.516 h   β^- 1.490     ^171Tm
                              ^172Er syn    49.3 h    β^- 0.891     ^172Tm

                                                                References

   Erbium ( IPA: /ˈɛː(r)biəm/) is a chemical element in the periodic table
   that has the symbol Er and atomic number 68. A rare silvery metallic
   lanthanide rare earth element, erbium is associated with several other
   rare elements in the mineral gadolinite from Ytterby in Sweden.

Notable characteristics

   A trivalent element, pure erbium metal is malleable (or easily shaped),
   soft yet stable in air and does not oxidize as quickly as some other
   rare-earth metals. Its salts are rose-colored and the element gives a
   characteristic sharp absorption spectra in visible light, ultraviolet,
   and near infrared. Otherwise it looks much like the other rare earths.
   Its sesquioxide is called erbia. Erbium's properties are to a degree
   dictated by the kind and amount of impurities present. Erbium does not
   play any known biological role but is thought by some to be able to
   stimulate metabolism. Erbium doped glasses or crystals can be used as
   optical amplification media, where erbium ions are optically pumped at
   around 980nm or 1480nm and then radiate light at 1550nm. This process
   can be used to create lasers and optical amplifiers. The 1550nm
   wavelength is especially important for optical communications becase
   standard single mode optical fibers have minimal loss at this
   particular wavelength.

Applications

   Erbium's everyday uses are varied. It is commonly used as a
   photographic filter and because of its resilience it is useful as a
   metallurgical additive. Other uses:
     * Used in nuclear technology as a neutron absorber.
     * Used as a dopant in fibre optic laser amplifiers.
     * When added to vanadium as an alloy erbium lowers hardness and
       improves workability.
     * Erbium oxide has a pink colour and is sometimes used as a colorant
       for glass and porcelain. The glass is then often used in sunglasses
       and cheap jewelry.
     * Erbium doped optical silica-glass fibers is the active element in
       erbium-doped fibre amplifiers (EDFAs) which are widely used in
       optical communications. The same fibers can be used to create fibre
       lasers. Co-doping of optical fiber with Er and Yb is used in high
       power Er/Yb fibre lasers, which gradually replace CO[2] lasers for
       metal welding and cutting applications. Erbium can also be used in
       erbium-doped waveguide amplifiers.

History

   Erbium (for Ytterby, a town in Sweden) was discovered by Carl Gustaf
   Mosander in 1843. Mosander separated "yttria" from the mineral
   gadolinite into three fractions which he called yttria, erbia, and
   terbia. He named the new element after the town of Ytterby where large
   concentrations of yttria and erbium are located. Erbia and terbia,
   however, were confused at this time. After 1860, terbia was renamed
   erbia and after 1877 what had been known as erbia was renamed terbia.
   Fairly pure Er[2]O[3] was independently isolated in 1905 by Georges
   Urbain and Charles James. Reasonably pure metal wasn't produced until
   1934 when workers reduced the anhydrous chloride with potassium vapor.

Occurrence

   Like other rare earths, this element is never found as a free element
   in nature but is found bound in monazite sand ores. It has historically
   been very difficult and expensive to separate rare earths from each
   other in their ores but ion-exchange production techniques developed in
   the late 20th century have greatly brought down the cost of production
   of all rare-earth metals and their chemical compounds. The principal
   commercial sources of erbium are from the minerals xenotime and
   euxenite. Metallic erbium in dust form presents a fire and explosion
   hazard.

Isotopes

   Naturally occurring erbium is composed of 6 stable isotopes, Er-162,
   Er-164, Er-166, Er-167, Er-168, and Er-170 with Er-166 being the most
   abundant (33.6% natural abundance). 23 radioisotopes have been
   characterized, with the most stable being Er-169 with a half life of
   9.4 days, Er-172 with a half-life of 49.3 hours, Er-160 with a
   half-life of 28.58 hours, Er-165 with a half-life of 10.36 hours, and
   Er-171 with a half life of 7.516 hours. All of the remaining
   radioactive isotopes have half-lifes that are less than 3.5 hours, and
   the majority of these have half lifes that are less than 4 minutes.
   This element also has 6 meta states, with the most stable being Er-167m
   (t[½] 2.269 seconds).

   The isotopes of erbium range in atomic weight from 144.957 amu (Er-145)
   to 173.944 amu (Er-174). The primary decay mode before the most
   abundant stable isotope, Er-166, is electron capture, and the primary
   mode after is beta decay. The primary decay products before Er-166 are
   element 67 (holmium) isotopes, and the primary products after are
   element 69 (thulium) isotopes.

Precautions

   As with the other lanthanides, erbium compounds are of low to moderate
   toxicity, although their toxicity has not been investigated in detail.

   Retrieved from " http://en.wikipedia.org/wiki/Erbium"
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   with only minor checks and changes (see www.wikipedia.org for details
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