Erbium | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Pronunciation | /ˈɜːrbiəm/ | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Appearance | silvery white | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Standard atomic weight Ar°(Er) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Erbium in the periodic table | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Atomic number (Z) | 68 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Group | f-block groups (no number) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Period | period 6 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Block | f-block | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electron configuration | [ Xe ] 4f12 6s2 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electrons per shell | 2, 8, 18, 30, 8, 2 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Physical properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Phase at STP | solid | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Melting point | 1802 K (1529 °C,2784 °F) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Boiling point | 3141 K(2868 °C,5194 °F) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density (at 20° C) | 9.065 g/cm3 [3] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
when liquid (at m.p.) | 8.86 g/cm3 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Heat of fusion | 19.90 kJ/mol | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Heat of vaporization | 280 kJ/mol | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molar heat capacity | 28.12 J/(mol·K) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vapor pressure
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Atomic properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Oxidation states | 0, [4] +1, +2, +3 (a basic oxide) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electronegativity | Pauling scale: 1.24 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ionization energies |
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Atomic radius | empirical:176 pm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Covalent radius | 189±6 pm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Spectral lines of erbium | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Other properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Natural occurrence | primordial | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Crystal structure | hexagonal close-packed (hcp)(hP2) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lattice constants | a = 355.93 pm c = 558.49 pm (at 20 °C) [3] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Thermal expansion | poly: 12.2 µm/(m⋅K)(r.t.) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Thermal conductivity | 14.5 W/(m⋅K) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electrical resistivity | poly: 0.860 µΩ⋅m(r.t.) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Magnetic ordering | paramagnetic at 300 K | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molar magnetic susceptibility | +44300.00×10−6 cm3/mol [5] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Young's modulus | 69.9 GPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shear modulus | 28.3 GPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bulk modulus | 44.4 GPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Speed of sound thin rod | 2830 m/s(at 20 °C) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Poisson ratio | 0.237 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vickers hardness | 430–700 MPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brinell hardness | 600–1070 MPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CAS Number | 7440-52-0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
History | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Naming | after Ytterby (Sweden), where it was mined | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Discovery | Carl Gustaf Mosander (1843) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isotopes of erbium | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Erbium is a chemical element; it has symbol Er and atomic number 68. A silvery-white [7] solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare-earth element, originally found in the gadolinite mine in Ytterby, Sweden, which is the source of the element's name.
Erbium's principal uses involve its pink-colored Er3+ ions, which have optical fluorescent properties particularly useful in certain laser applications. Erbium-doped glasses or crystals can be used as optical amplification media, where Er3+ ions are optically pumped at around 980 or 1480 nm and then radiate light at 1530 nm in stimulated emission. This process results in an unusually mechanically simple laser optical amplifier for signals transmitted by fiber optics. The 1550 nm wavelength is especially important for optical communications because standard single mode optical fibers have minimal loss at this particular wavelength.
In addition to optical fiber amplifier-lasers, a large variety of medical applications (e.g. dermatology, dentistry) rely on the erbium ion's 2940 nm emission (see Er:YAG laser) when lit at another wavelength, which is highly absorbed in water in tissues, making its effect very superficial. Such shallow tissue deposition of laser energy is helpful in laser surgery, and for the efficient production of steam which produces enamel ablation by common types of dental laser.
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 has characteristic sharp absorption spectra bands in visible light, ultraviolet, and near infrared. [8] 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 to be able to stimulate metabolism. [9]
Erbium is ferromagnetic below 19 K, antiferromagnetic between 19 and 80 K and paramagnetic above 80 K. [10]
Erbium can form propeller-shaped atomic clusters Er3N, where the distance between the erbium atoms is 0.35 nm. Those clusters can be isolated by encapsulating them into fullerene molecules, as confirmed by transmission electron microscopy. [11]
Like most rare-earth elements, erbium is usually found in the +3 oxidation state. However, it is possible for erbium to also be found in the 0, +1 and +2 oxidation states.
Erbium metal retains its luster in dry air, however will tarnish slowly in moist air and burns readily to form erbium(III) oxide: [12]
Erbium is quite electropositive and reacts slowly with cold water and quite quickly with hot water to form erbium hydroxide: [13]
Erbium metal reacts with all the halogens: [14]
Erbium dissolves readily in dilute sulfuric acid to form solutions containing hydrated Er(III) ions, which exist as rose red [Er(OH2)9]3+ hydration complexes: [14]
Naturally occurring erbium is composed of 6 stable isotopes, 162
Er
, 164
Er
, 166
Er
, 167
Er
, 168
Er
, and 170
Er
, with 166
Er
being the most abundant (33.503% natural abundance). 29 radioisotopes have been characterized, with the most stable being 169
Er
with a half-life of 9.4 d, 172
Er
with a half-life of 49.3 h, 160
Er
with a half-life of 28.58 h, 165
Er
with a half-life of 10.36 h, and 171
Er
with a half-life of 7.516 h. All of the remaining radioactive isotopes have half-lives that are less than 3.5 h, and the majority of these have half-lives that are less than 4 minutes. This element also has 13 meta states, with the most stable being 167m
Er
with a half-life of 2.269 s. [15]
The isotopes of erbium range in atomic weight from 142.9663 u (143
Er
) to 176.9541 u (177
Er
). The primary decay mode before the most abundant stable isotope, 166
Er
, is electron capture, and the primary mode after is beta decay. The primary decay products before 166
Er
are element 67 (holmium) isotopes, and the primary products after are element 69 (thulium) isotopes. [15]
Erbium(III) oxide (also known as erbia) is the only known oxide of erbium, first isolated by Carl Gustaf Mosander in 1843, and first obtained in pure form in 1905 by Georges Urbain and Charles James. [16] It has a cubic structure resembling the bixbyite motif. The Er3+ centers are octahedral. [17] The formation of erbium oxide is accomplished by burning erbium metal. [18] Erbium oxide is insoluble in water and soluble in mineral acids.
Erbium(III) fluoride is a pinkish powder [19] that can be produced by reacting erbium(III) nitrate and ammonium fluoride. [20] It can be used to make infrared light-transmitting materials [21] and up-converting luminescent materials. [22] Erbium(III) chloride is a violet compounds that can be formed by first heating erbium(III) oxide and ammonium chloride to produce the ammonium salt of the pentachloride ([NH4]2ErCl5) then heating it in a vacuum at 350-400 °C. [23] [24] [25] It forms crystals of the AlCl3 type, with monoclinic crystals and the point group C2/m. [26] Erbium(III) chloride hexahydrate also forms monoclinic crystals with the point group of P2/n (P2/c) - C42h. In this compound, erbium is octa-coordinated to form [Er(H2O)6Cl2]+ ions with the isolated Cl− completing the structure. [27]
Erbium(III) bromide is a violet solid. It is used, like other metal bromide compounds, in water treatment, chemical analysis and for certain crystal growth applications. [28] Erbium(III) iodide [29] is a slightly pink compound that is insoluble in water. It can be prepared by directly reacting erbium with iodine. [30]
Organoerbium compounds are very similar to those of the other lanthanides, as they all share an inability to undergo π backbonding. They are thus mostly restricted to the mostly ionic cyclopentadienides (isostructural with those of lanthanum) and the σ-bonded simple alkyls and aryls, some of which may be polymeric. [31]
Erbium (for Ytterby, a village in Sweden) was discovered by Carl Gustaf Mosander in 1843. [32] Mosander was working with a sample of what was thought to be the single metal oxide yttria, derived from the mineral gadolinite. He discovered that the sample contained at least two metal oxides in addition to pure yttria, which he named "erbia" and "terbia" after the village of Ytterby where the gadolinite had been found. Mosander was not certain of the purity of the oxides and later tests confirmed his uncertainty. Not only did the "yttria" contain yttrium, erbium, and terbium; in the ensuing years, chemists, geologists and spectroscopists discovered five additional elements: ytterbium, scandium, thulium, holmium, and gadolinium. [33] : 701 [34] [35] [36] [37] [38]
Erbia and terbia, however, were confused at this time. A spectroscopist mistakenly switched the names of the two elements during spectroscopy. After 1860, terbia was renamed erbia and after 1877 what had been known as erbia was renamed terbia. Fairly pure Er2 O 3 was independently isolated in 1905 by Georges Urbain and Charles James. Reasonably pure erbium metal was not produced until 1934 when Wilhelm Klemm and Heinrich Bommer reduced the anhydrous chloride with potassium vapor. [39] It was only in the 1990s that the price for Chinese-derived erbium oxide became low enough for erbium to be considered for use as a colorant in art glass. [40]
The concentration of erbium in the Earth crust is about 2.8 mg/kg and in seawater 0.9 ng/L. [41] (Concentration of less abundant elements may vary with location by several orders of magnitude [42] making the relative abundance unreliable). 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 chromatography methods [43] developed in the late 20th century have greatly reduced 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, and most recently, the ion adsorption clays of southern China. Consequently, China has now become the principal global supplier of this element. [44] In the high-yttrium versions of these ore concentrates, yttrium is about two-thirds of the total by weight, and erbia is about 4–5%. When the concentrate is dissolved in acid, the erbia liberates enough erbium ion to impart a distinct and characteristic pink color to the solution. This color behavior is similar to what Mosander and the other early workers in the lanthanides would have seen in their extracts from the gadolinite minerals of Ytterby.
Crushed minerals are attacked by hydrochloric or sulfuric acid that transforms insoluble rare-earth oxides into soluble chlorides or sulfates. The acidic filtrates are partially neutralized with caustic soda (sodium hydroxide) to pH 3–4. Thorium precipitates out of solution as hydroxide and is removed. After that the solution is treated with ammonium oxalate to convert rare earths into their insoluble oxalates. The oxalates are converted to oxides by annealing. The oxides are dissolved in nitric acid that excludes one of the main components, cerium, whose oxide is insoluble in HNO3. The solution is treated with magnesium nitrate to produce a crystallized mixture of double salts of rare-earth metals. The salts are separated by ion exchange. In this process, rare-earth ions are sorbed onto suitable ion-exchange resin by exchange with hydrogen, ammonium or cupric ions present in the resin. The rare earth ions are then selectively washed out by suitable complexing agent. [41] Erbium metal is obtained from its oxide or salts by heating with calcium at 1450 °C under argon atmosphere. [41]
A large variety of medical applications (i.e. dermatology, dentistry) utilize erbium ion's 2940 nm emission (see Er:YAG laser), which is highly absorbed in water (absorption coefficient about 12000/cm). Such shallow tissue deposition of laser energy is necessary for laser surgery, and the efficient production of steam for laser enamel ablation in dentistry. [45]
Erbium-doped optical silica-glass fibers are the active element in erbium-doped fiber amplifiers (EDFAs), which are widely used in optical communications. [46] The same fibers can be used to create fiber lasers. In order to work efficiently, erbium-doped fiber is usually co-doped with glass modifiers/homogenizers, often aluminium or phosphorus. These dopants help prevent clustering of Er ions and transfer the energy more efficiently between excitation light (also known as optical pump) and the signal. Co-doping of optical fiber with Er and Yb is used in high-power Er/Yb fiber lasers. Erbium can also be used in erbium-doped waveguide amplifiers. [9]
When added to vanadium as an alloy, erbium lowers hardness and improves workability. [42] An erbium-nickel alloy Er3Ni has an unusually high specific heat capacity at liquid-helium temperatures and is used in cryocoolers; a mixture of 65% Er3 Co and 35% Er0.9 Yb 0.1Ni by volume improves the specific heat capacity even more. [47] [48]
Erbium oxide has a pink color, and is sometimes used as a colorant for glass, cubic zirconia and porcelain. The glass is then often used in sunglasses and cheap jewelry. [42] [49]
Erbium is used in nuclear technology in neutron-absorbing control rods. [9] [50] or as a burnable poison in nuclear fuel design. [51]
Erbium does not have a biological role, but erbium salts can stimulate metabolism. Humans consume 1 milligram of erbium a year on average. The highest concentration of erbium in humans is in the bones, but there is also erbium in the human kidneys and liver. [9] Erbium is slightly toxic if ingested, but erbium compounds are not toxic. [9] Metallic erbium in dust form presents a fire and explosion hazard. [52] [53] [54]
Dysprosium is a chemical element; it has symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is 164Dy.
Gadolinium is a chemical element; it has symbol Gd and atomic number 64. Gadolinium is a silvery-white metal when oxidation is removed. It is a malleable and ductile rare-earth element. Gadolinium reacts with atmospheric oxygen or moisture slowly to form a black coating. Gadolinium below its Curie point of 20 °C (68 °F) is ferromagnetic, with an attraction to a magnetic field higher than that of nickel. Above this temperature it is the most paramagnetic element. It is found in nature only in an oxidized form. When separated, it usually has impurities of the other rare-earths because of their similar chemical properties.
Holmium is a chemical element; it has symbol Ho and atomic number 67. It is a rare-earth element and the eleventh member of the lanthanide series. It is a relatively soft, silvery, fairly corrosion-resistant and malleable metal. Like many other lanthanides, holmium is too reactive to be found in native form, as pure holmium slowly forms a yellowish oxide coating when exposed to air. When isolated, holmium is relatively stable in dry air at room temperature. However, it reacts with water and corrodes readily, and also burns in air when heated.
The lanthanide or lanthanoid series of chemical elements comprises at least the 14 metallic chemical elements with atomic numbers 57–70, from lanthanum through ytterbium. In the periodic table, they fill the 4f orbitals. Lutetium is also sometimes considered a lanthanide, despite being a d-block element and a transition metal.
Neodymium is a chemical element; it has symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly producing pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states. It is generally regarded as having one of the most complex spectra of the elements. Neodymium was discovered in 1885 by the Austrian chemist Carl Auer von Welsbach, who also discovered praseodymium. It is present in significant quantities in the minerals monazite and bastnäsite. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. Neodymium is fairly common—about as common as cobalt, nickel, or copper—and is widely distributed in the Earth's crust. Most of the world's commercial neodymium is mined in China, as is the case with many other rare-earth metals.
Scandium is a chemical element; it has symbol Sc and atomic number 21. It is a silvery-white metallic d-block element. Historically, it has been classified as a rare-earth element, together with yttrium and the lanthanides. It was discovered in 1879 by spectral analysis of the minerals euxenite and gadolinite from Scandinavia.
Terbium is a chemical element; it has the symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, and ductile. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with water, evolving hydrogen gas. Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime and euxenite.
Thulium is a chemical element; it has symbol Tm and atomic number 69. It is the thirteenth element in the lanthanide series of metals. It is the second-least abundant lanthanide in the Earth's crust, after radioactively unstable promethium. It is an easily workable metal with a bright silvery-gray luster. It is fairly soft and slowly tarnishes in air. Despite its high price and rarity, thulium is used as a dopant in solid-state lasers, and as the radiation source in some portable X-ray devices. It has no significant biological role and is not particularly toxic.
Ytterbium is a chemical element; it has symbol Yb and atomic number 70. It is a metal, the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. Like the other lanthanides, its most common oxidation state is +3, as in its oxide, halides, and other compounds. In aqueous solution, like compounds of other late lanthanides, soluble ytterbium compounds form complexes with nine water molecules. Because of its closed-shell electron configuration, its density, melting point and boiling point are much lower than those of most other lanthanides.
Group 3 is the first group of transition metals in the periodic table. This group is closely related to the rare-earth elements. It contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr). The group is also called the scandium group or scandium family after its lightest member.
Carl Gustaf Mosander was a Swedish chemist. He discovered the rare earth elements lanthanum, erbium and terbium.
Neodymium(III) chloride or neodymium trichloride is a chemical compound of neodymium and chlorine with the formula NdCl3. This anhydrous compound is a mauve-colored solid that rapidly absorbs water on exposure to air to form a purple-colored hexahydrate, NdCl3·6H2O. Neodymium(III) chloride is produced from minerals monazite and bastnäsite using a complex multistage extraction process. The chloride has several important applications as an intermediate chemical for production of neodymium metal and neodymium-based lasers and optical fibers. Other applications include a catalyst in organic synthesis and in decomposition of waste water contamination, corrosion protection of aluminium and its alloys, and fluorescent labeling of organic molecules (DNA).
Marc Delafontaine was a Swiss chemist and spectroscopist who was involved in discovering and investigating some of the rare earth elements.
Yttrium oxide, also known as yttria, is Y2O3. It is an air-stable, white solid substance.
Erbium(III) chloride is a violet solid with the formula ErCl3. It is used in the preparation of erbium metal.
Holmium(III) oxide, or holmium oxide is a chemical compound of a rare-earth element holmium and oxygen with the formula Ho2O3. Together with dysprosium(III) oxide (Dy2O3), holmium oxide is one of the most powerfully paramagnetic substances known. The oxide, also called holmia, occurs as a component of the related erbium oxide mineral called erbia. Typically, the oxides of the trivalent lanthanides coexist in nature, and separation of these components requires specialized methods. Holmium oxide is used in making specialty colored glasses. Glass containing holmium oxide and holmium oxide solutions have a series of sharp optical absorption peaks in the visible spectral range. They are therefore traditionally used as a convenient calibration standard for optical spectrophotometers.
Erbium(III) oxide is the inorganic compound with the formula Er2O3. It is a pink paramagnetic solid. It finds uses in various optical materials.
Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89Y is the only stable isotope and the only isotope found in the Earth's crust.
A dopant is a small amount of a substance added to a material to alter its physical properties, such as electrical or optical properties. The amount of dopant is typically very low compared to the material being doped.
Erbium compounds are compounds containing the element erbium (Er). These compounds are usually dominated by erbium in the +3 oxidation state, although the +2, +1 and 0 oxidation states have also been reported.
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