dysprosium

Dy. Atomic number 66. Electron configuration [Xe]4f ¹⁰ 6s ^2. Lanthanide element in group 3 of the periodic table. A member of the yttrium group of rare earth elements. Atomic weight 162.500(1). Seven stable isotopes are known: mass numbers 156 (0.056(3)%), 158 (0.095(3)%), 160 (2.329(18)%), 161 (18.889(42)%), 162 (25.475(36)%), 163 (24.896(42)%), and 164 (28.260(54)%). Radioactive isotopes with mass numbers between 138 and 173 are also known. In 1886, PEL de Boisbaudran discovered its presence in holmium compounds. The element's name comes from the Greek δυσπροσιτο (dysprositos), meaning "hard to obtain." It is found in gadolinite and fergusonite. Its abundance in the earth's crust is 3.7 ppm. China is the leading producer of rare earth elements, accounting for approximately 98% (as of 2006). Medium and heavy rare earths, including Dy, are only produced in Southern China. China is the leading producer of rare earth elements with 30%, followed by Russia with 22% and the United States with 15%. Its melting point is 1412 °C, boiling point 2562 °C. Density is 8.55 g cm ^-3 (20 °C). First ionization energy is 5.939 eV. Oxidation number is 3. The outer shell electron configuration of the ^{Dy 3+} ion is 4f ⁹ , and the salt is strongly magnetic (magnetic moment 10.55 μ _B ). Like other rare earth elements, it forms a compound with Dy ^III . The crystals and aqueous solutions are yellow or yellow-green, and like holmium compounds, they are extremely paramagnetic. The most important use of Dy is as an additive to increase the coercive force and magnetic flux density of Nd-Fe-B (neodymium) magnets (see other terms for rare earth magnets) at high temperatures, and its price has risen sharply in recent years. [CAS 7429-91-6]

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

Dy．原子番号66の元素．電子配置[Xe]4f ¹⁰6s²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．原子量162.500(1)．質量数156(0.056(3)％)，158(0.095(3)％)，160(2.329(18)％)，161(18.889(42)％)，162(25.475(36)％)，163(24.896(42)％)，164(28.260(54)％)の7種の安定同位体と，質量数138～173の放射性同位体が知られている．1886年，ホルミウム化合物中に存在することをP.E.L. de Boisbaudranが発見した．元素名はギリシア語で“得がたい”を意味するδυσπροσιτο(dysprositos)から．ガドリン石，フェルグソン石などに含まれる．地殻中の存在度3.7 ppm．希土類元素全体の生産量首位は中国で約98％(2006年)を占める．Dyを含む中重希土類は華南地域でのみ産出する．希土類埋蔵量首位は中国30％，ついでロシア諸国22％，アメリカ15％．融点1412 ℃，沸点2562 ℃．密度8.55 g cm^－3(20 ℃)．第一イオン化エネルギー5.939 eV．酸化数3．Dy^3＋ イオンの外殻電子配置は4f ⁹で塩は強い磁性を示す(磁気能率10.55μ_B)．ほかの希土類元素と同様 Dy^Ⅲで化合物をつくる．結晶および水溶液は黄または黄緑色で，ホルミウムの化合物と同様にいちじるしい常磁性を示す．Dyのもっとも重要な用途は，Nd-Fe-B(ネオジム)磁石([別用語参照]希土類磁石)の高温域の保磁力・磁束密度を高めるはたらきをもつ添加剤で，近年価格が急上昇している．[CAS 7429-91-6]

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