エルビウム 化学特性,用途語,生産方法
解説
エルビウム，Er．原子番号68の元素．電子配置[Kr]4f 126s2の周期表3族ランタノイド元素．希土類元素イットリウム族の一つ．元素名はガドリン石の最初の発見地スウェーデンのytterbyにちなんで命名された．1843年スウェーデンのC.G. Mosanderがイットリウム試料中に発見した．もともとMosanderは，現在テルビウムと命名された元素をエルビウムとしていた．原子量167.259(3)．質量数162(0.139(5)％)，164(1.601(3)％)，166(33.503(36)％)，167(22.869(9)％)，168(26.978(18)％)，170(14.910(36)％)の6種の安定同位体と，質量数143～177の放射性同位体が知られている．地殻中の存在度2.2 ppm．ガドリン石，フェルグソン石，ゼノタイムなどに存在する．分離は困難で，溶媒抽出，錯体形成，イオン交換クロマトグラフィーの組合せで行われる．純金属はErF3のカルシウム金属による還元で得られる．融点1529 ℃，沸点2863 ℃．第一イオン化エネルギー6.108 eV．密度9.066 g cm－3．酸化数3．Er3＋ の電子配置は4f11でいちじるしい常磁性を示す．化学的性質は一般の希土類元素と同じく，シュウ酸塩，リン酸塩，水酸化物，フッ化物，炭酸塩などは水に難溶．結晶および水溶液は赤色を示す．Er2O3は赤色ガラス用添加剤．Er：YAGレーザーは赤外線高出力レーザーで，歯科治療用などに用いられる．Erドープ光ファイバー(EDFA)は光増幅器に用いられる．
化学的特性
grey powder
物理的性質
Erbium is a soft, malleable metal with a silvery metallic luster that only tarnishes (oxidizes)slightly in air. It is one of the rare-earths of the yttrium subgroup of the lanthanide series.
Its melting point is 1,529°C, its boiling point is 2,868°C, and its density is 9.07g/cm
3.
同位体
There are 39 isotopes of erbium, six of which are stable: Er-162, Er-164, Er-166,Er-167, Er-168, and Er-170. These six isotopes make up the total atomic weight (mass)of erbium, and all the other isotopes are artificially made and short-lived. Their half-livesrange from 200 nanoseconds to 49 hours.
名前の由来
Named for the quarry in Ytterby, Sweden, where ores and minerals of
many elements are found.
天然物の起源
Erbium ranks 17th in abundance among the rare-earths, and it is the 46th most abundantelement found in the Earth’s crust. It exists in only 2.5 ppm, meaning that about 2.5 poundsof erbium could be extracted from one million pounds of dirt in the Earth’s crust. Higher concentrationsare found in some areas, but in general, the oxides of erbium are rather scarce.It is found in ores such as monazite, gadolinite, and bastnasite. It was first separated intothree elements in 1843 (yttria, erbia, and terbia). Erbium is also produced as a by-product ofnuclear fission of uranium.
来歴
Erbium, one of the so-called rare-earth elements of the lanthanide series, is found in the minerals mentioned under dysprosium above. In 1842 Mosander separated “yttria,” found in the mineral gadolinite, into three fractions which he called yttria, erbia, and terbia. The names erbia and terbia became confused in this early period. After 1860, Mosander’s terbia was known as erbia, and after 1877, the earlier known erbia became terbia. The erbia of this period was later shown to consist of five oxides, now known as erbia, scandia, holmia, thulia and ytterbia. By 1905 Urbain and James independently succeeded in isolating fairly pure Er
2O
3. Klemm and Bommer first produced reasonably pure erbium metal in 1934 by reducing the anhydrous chloride with potassium vapor. The pure metal is soft and malleable and has a bright, silvery, metallic luster. As with other rare-earth metals, its properties depend to a certain extent on the impurities present. The metal is fairly stable in air and does not oxidize as rapidly as some of the other rare-earth metals. Naturally occurring erbium is a mixture of six isotopes, all of which are stable. Twenty-seven radioactive isotopes of erbium are also recognized. Recent production techniques, using ion-exchange reactions, have resulted in much lower prices of the rare-earth metals and their compounds in recent years. The cost of 99.9% erbium metal is about $21/g. Erbium is finding nuclear and metallurgical uses. Added to vanadium, for example, erbium lowers the hardness and improves workability. Most of the rare-earth oxides have sharp absorption bands in the visible, ultraviolet, and near infrared. This property, associated with the electronic structure, gives beautiful pastel colors to many of the rare-earth salts. Erbium oxide gives a pink color and has been used as a colorant in glasses and porcelain enamel glazes.
特性
Although erbium is magnetic at very low temperatures, it is antiferromagnetic and becomesa superconductor at temperatures near absolute zero. It is insoluble in water but soluble inacids. Its salts range from pink to red. Erbium and some of the other rare-earth elements areconsidered to be “impurities” in the minerals in which they are found. Small quantities oferbium can also be separated from several other rare-earths.
使用
Erbium has application in glass coloring, as an amplifier in fiber optics, and in lasers for medical and dental use.
It is commonly used as a photographic filter, and because of its resilience it is useful as a metallurgical additive.
The Erbium ion has a very narrow absorption band coloring erbium salts pink. It is therefore used in eyeware and decorative glassware. It can neutralize discoloring impurities such as ferric ions and produce a neutral gray shade. It is used in a variety of glass products for this purpose.
Lasers based on Er:YAG are ideally suited for surgical applications because of its ability to deliver energy without thermal build-up in tissue.
Erbium Metal, is mainly metallurgical uses. Added to vanadium, for example, Erbium lowers hardness and improves workability. There are also a few applications for nuclear industry. Erbium Metal can be further processed to various shapes of ingots, pieces, wires, foils, slabs, rods, discs and powder.
定義
A soft malleable silvery
element of the lanthanoid series of
metals. It occurs in association with other
lanthanoids. Erbium has uses in the metallurgical
and nuclear industries and in making
glass for absorbing infrared radiation.
Symbol: Er; m.p. 1529°C; b.p. 2863°C;
r.d. 9.066 (25°C); p.n. 68; r.a.m. 167.26.
危険性
Erbium nitrate [Er(NO
3)
3] may explode when “shocked” or at high temperatures. As withother rare-earths, erbium and its compounds should be handled with care because they canbe toxic.
エルビウム 上流と下流の製品情報
原材料
準備製品