gadolinium

Japanese: ガドリニウム

Gd. Atomic number 64. Electron configuration [Xe] ^4f75d16s2 . Lanthanide element in group ³ of the periodic table. A member of the yttrium group of rare earth elements. Atomic weight 157.25(3). Seven stable isotopes are known ^: mass numbers 152 (0.20(1)%), 154 (2.18(3)%), 155 (14.80(12)%), 156 (20.47(9)%), 157 (15.65(2)%), 158 (24.84(7)%), and 160 (21.86(19)%). Radioactive isotopes with mass numbers between 136 and 169 are also known. It was isolated from samarskite by C. de Marignac in 1880. The element's name comes from the mineral gadolinite, named after the Finnish scientist J. Gadolin. Its abundance in the earth's crust is 3.3 ppm. It is found in xenotime, allanite, etc. It is separated by solvent extraction. For high purity (> 99.9999%), ion exchange is used. Its melting point is 1313 °C, boiling point 3266 °C, density 7.90 g cm ^-3 , first ionization energy 6.150 eV. The metal is ferromagnetic below 293 K, and it has been used for magnetic cooling to create extremely low temperatures of about 0.001 K. Only the compound ^{Gd III} is known. The electron configuration of Gd ^III is 4f ⁷ , and the compound is also strongly magnetic. Its aqueous solution is generally colorless. Like other rare earth elements, its oxalates, phosphates, fluorides, and carbonates are poorly soluble in water. EDTA complexes are used as contrast agents for MRI, (Y, Gd)BO ₃ :Eu and (Y, Gd)BO ₃ :Tb are used as red and green phosphors for color televisions and fluorescent lamps, respectively, and Gd ₂ O ₂ S is used as a cold storage material for small refrigerators. [CAS 7440-54-2]

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

Japanese:

Gd．原子番号64の元素．電子配置[Xe]4f⁷5d¹6s²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157.25(3)．質量数152(0.20(1)％)，154(2.18(3)％)，155(14.80(12)％)，156(20.47(9)％)，157(15.65(2)％)，158(24.84(7)％)，160(21.86(19)％)の7種の安定同位体と，質量数136～169の放射性同位体が知られている．1880年，C. de Marignacがサマルスキー石から分離した．元素名は，フィンランドの科学者J. Gadolinの名前をとった鉱石ガドリン石からとされる．地殻中の存在度3.3 ppm．ゼノタイム，褐れん石などに含まれる．分離は溶媒抽出法による．高純度( ＞ 99.9999％)のものはイオン交換法が使われる．融点1313 ℃，沸点3266 ℃．密度7.90 g cm^－3．第一イオン化エネルギー6.150 eV．金属は293 K 以下で強磁性を示し，0.001 K 程度の極低温をつくる磁気冷却に利用された．Gd^Ⅲの化合物のみが知られる．Gd^Ⅲの電子配置は4f⁷で，化合物も強い磁性を示す．水溶液は一般に無色である．ほかの希土類と同じく，シュウ酸塩，リン酸塩，フッ化物，炭酸塩などは水に難溶．EDTA錯体はMRI用の造影剤，(Y，Gd)BO₃：Euは赤色，(Y，Gd)BO₃：Tbは緑色カラーテレビジョン用または蛍光灯用の蛍光体，Gd₂O₂Sは小型冷凍機用蓄冷材として用いられる．[CAS 7440-54-2]