yttrium

Japanese: イットリウム

Y. Atomic number 39. Lanthanide element in group ³ of the periodic table with electron configuration [Kr] ^4d15s2 . One of the rare earth elements of the yttrium group. Initially, its discoverer J. Gadolin named the element ytterbium after the name of the Swedish village Ytterby, where the mineral gadolinite is found, but it was later shortened to yttrium, and ytterbium was given to the 70th element. Udagawa Yoan named it yttrium in his book Shamitsu Kaisou, published in 1837. Atomic weight 88.90585(2). A stable isotope with mass number 89 (100%) and radioactive isotopes with mass numbers 76 to 108 are known. It was discovered by J. Gadolin in 1794, and isolated by C. G. Mosander in 1843. It is included in gadolinite, monazite, xenotime, etc.
Abundance in the earth's crust is 20 ppm. China has the largest deposits, followed by the United States and Australia. A grey metal obtained by reduction of YF ₃ with Ca metal. Melting point 1522 °C, boiling point 3338 °C. Density 4.47 g cm ^-3 (hexagonal crystal system). Standard electrode potential Y ³⁺ /Y-2.37 V. First ionization energy 6.38 eV. Easily oxidized in air. Soluble in acid, insoluble in alkali. Included in the rare earth elements, but with 4d ¹ 5s ² outer shell electrons, it is a d group element. Its ionic radius is 0.106 nm, close to that of Dy and Ho. Oxidation number 3. Its properties are similar to those of Dy and Ho compounds. Compounds are generally colorless. Like rare earth elements, its oxides, fluorides, oxalates, and hydroxides are insoluble in water, while its chlorides and sulfates are easily soluble in water. Yttrium hydroxide is weaker than lanthanum, but still has a fairly strong base.
YBa ₂ Cu ₃ O ₇ (YBCO) is a high-temperature superconductor with a superconducting transition temperature of -93 K (-180 °C). Yttrium oxide Y ₂ O ₃ is used in large quantities in color televisions and other devices as a europium-activated red phosphor. Y ₂ O ₃ is a raw material for ceramics that are transparent to visible light. Eu: Y ₂ O ₂ S is famous for its use in X-ray image intensifiers, while YAG (yttrium aluminium garnet): Y ₃ Al ₅ O ₁₂ is famous for its use in laser elements. YIG (yttrium iron garnet): Y ₃ Fe ₅ O ₁₂ is used, for example, in mobile phone components as a high-frequency isolator. [CAS 7440-65-5]

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

Japanese:

Y．原子番号39の元素．電子配置[Kr]4d¹5s²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．当初，発見者のJ. Gadolinは元素名を，鉱物ガドリン石の産地スウェーデンの村名ytterbyにちなんでytterbiumとしたが，のちにyttriumに短縮され，ytterbiumは70番元素に与えられた．宇田川榕菴は，天保8年(1837年)に出版した「舎密開宗」で依多母(イトリュウム)としている．原子量88.90585(2)．質量数89(100％)の安定同位体と，質量数76～108までの放射性同位体が知られている．1794年にJ. Gadolinにより発見され，分離は，1843年，C.G. Mosanderによりなされた．ガドリン石，モナズ石，ゼノタイムなどに含まれる．
地殻中の存在度20 ppm．埋蔵量一位は中国，ついでアメリカ，オーストラリア．灰色の金属でYF₃のCa金属による還元で得られる．融点1522 ℃，沸点3338 ℃．密度4.47 g cm^－3(六方晶系)．標準電極電位 Y^3＋/Y－2.37 V．第一イオン化エネルギー6.38 eV．空気中では容易に酸化される．酸に可溶，アルカリに不溶．希土類元素に含めるが，外殻電子は4d¹5s²でdグループの元素．イオン半径は0.106 nm でDy，Hoに近い．酸化数3．DyやHoの化合物に似た性質を示す．化合物は一般に無色．希土類と同様に酸化物，フッ化物，シュウ酸塩，水酸化物などは水に不溶，塩化物，硫酸塩は水に易溶．イットリウムの水酸化物はランタンよりは弱いが，かなり強い塩基性をもっている．
YBa₂Cu₃O₇(YBCO)は高温超伝導体の一つで，超伝導転移温度－93 K(－180 ℃)．酸化イットリウムY₂O₃はユウロピウム賦活赤色蛍光体として，カラーテレビなどに多量に使用されている．Y₂O₃は可視光に透明なセラミックスの原料となる．Eu：Y₂O₂SはX線イメージインテンシファイア，YAG(yttrium aluminium garnet)：Y₃Al₅O₁₂はレーザー素子として有名である．YIG(yttrium iron garnet)：Y₃Fe₅O₁₂は，たとえば高周波用アイソレーターとして携帯電話の部品に用いられる．[CAS 7440-65-5]