neodymium

Nd. Atomic number 60. Electron configuration [Xe] ^4f46s2 . Lanthanide element in group ³ of the periodic table. A member of the cerium group of rare earth elements. Atomic weight 144.242(3). Seven stable isotopes are known: mass numbers 142 (27.2(5)%), 143 (12.2(2)%), 144 (23.8(3)%), 145 (8.3(1)%), 146 (17.2(3)%), 148 (5.7(1)%), and 150 (5.6(2)%). Radioactive isotopes with mass numbers between 124 and 161 are also known. In 1842, CG Mosander claimed to have discovered a new element, and named it didymium from the Greek word διδυμο (didymos), meaning twin, because its properties were "like a twin" with lanthanum and it existed together. In 1885, CF Auer von Welsbach further divided it into two and named one neoymium, combining the Greek word νεο (neos), meaning "new," with Mosander's "twin." The other is praseodymium. The Japanese name is a transliteration of the German name for the element (Neodym).
It is found in monazite and bastnaesite. Its abundance in the earth's crust is 16 ppm. China is the main producer of rare earth elements in general, accounting for about 98% (2007). China has the largest rare earth reserves with 30%, followed by Russia with 22% and the United States with 15%. The metal is obtained by reducing fluorides with Ca at high temperatures above 1000 °C, or by molten salt electrolysis of chlorides. It is a pale yellow-silver-white metal. It exists in two modifications: α (hexagonal close-packed) and β (body-centered cubic lattice) at 862 °C or higher. Its density is 7.007 g cm ^-3 (20 °C). Its melting point is 1021 °C, and its boiling point is 3068 °C. Its standard electrode potential is Nd ³⁺ /Nd - 2.32 V. Its first ionization energy is 5.525 eV. It is soluble in dilute acids and hot water. It is oxidized in air (room temperature) to form an oxide film. Oxidation number 3. The electron configuration of ^Nd3+ is ^4f3 and it is paramagnetic. The color of ^Nd3 compounds is often red to reddish purple. The same is true for aqueous solutions.
Nd ₂ O ₃ is blue (purple), and glass containing it is called neodymium glass. It absorbs light around 580 nm (yellow), so it is used in light bulbs and glass eyeglasses. Phosphates, fluorides, and oxalates are poorly soluble in water. Nd:YAG (Nd:Y ₃ Al ₅ O ₁₂ ) is a dopant for lasers. Nd ₂ Fe ₁₄ B, invented and developed in Japan in 1982, is currently the strongest permanent magnet (brand name Neomax) ([see other terms] rare earth magnet), and is used in a wide range of applications, including computer hard disk drives, vibration motors and speakers for mobile phones, MRI devices, motors for driving electric vehicles, and synchrotron radiation insertion sources (undulators). [CAS 7440-00-8]

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

Nd．原子番号60の元素．電子配置[Xe]4f ⁴6s²の周期表3族ランタノイド元素．希土類元素セリウム族の一つ．原子量144.242(3)．質量数142(27.2(5)％)，143(12.2(2)％)，144(23.8(3)％)，145(8.3(1)％)，146(17.2(3)％)，148(5.7(1)％)，150(5.6(2)％)の7種の安定同位体と，質量数124～161の放射性同位体が知られている．1842年，C.G. Mosanderが新元素を発見したとして，性質がランタンと“双子のように”似ていて一緒に存在していたことから，ギリシア語の双子を意味するδιδυμο(didymos)によってジジム(didymium)と名づけたが，1885年に至り，C.F. Auer von Welsbach(ウェルスバッハ)がこれをさらに二分割して，一方をギリシア語の“新しい”νεο(neos)とMosanderの“双子”を併せてneodymiumと命名した．他方はプラセオジムである．日本語名はドイツ語の元素名(Neodym)の音訳．
モナズ石，バストネス石(バストネサイト)などに存在する．地殻中の存在度16 ppm．希土類元素全般の主要産出国は中国で約98％(2007年)を占めている．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％．金属は1000 ℃ 以上の高温におけるフッ化物のCaによる還元，または塩化物の溶融塩電解で得られる．淡黄銀白色の金属．α(六方最密)と862 ℃ 以上のβ(体心立方格子)の二変態がある．密度7.007 g cm^－3(20 ℃)．融点1021 ℃，沸点3068 ℃．標準電極電位 Nd^3＋/Nd － 2.32 V．第一イオン化エネルギー5.525 eV．希酸，熱水に可溶．空気中(室温)で酸化され酸化皮膜をつくる．酸化数3．Nd^3＋ の電子配置は4f ³で常磁性．Nd^Ⅲ化合物の色は赤～赤紫が多い．水溶液も同様．
Nd₂O₃は青(紫)色で，これを含むガラスはネオジムガラスとよばれ，580 nm 付近(黄色)の光線を吸収するので電球用やガラス細工用眼鏡に使われる．リン酸塩，フッ化物，シュウ酸塩は水に難溶．Nd：YAG(Nd：Y₃Al₅O₁₂)はレーザー用ドーパント．1982年に日本で発明・開発されたNd₂Fe₁₄Bは，現在，最強の永久磁石(商品名ネオマックス)([別用語参照]希土類磁石)であり，コンピューター・ハードディスクドライブ，携帯電話用振動モーター・スピーカー，MRI装置，電気自動車駆動用モーター，放射光挿入光源(アンジュレーター)用など多方面に利用されている．[CAS 7440-00-8]

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