Holmium (Ho)
lanthanideSolid
標準原子量
164.93033 u電子配置
[Xe] 6s2 4f11融点
1473.85 °C沸点
2699.85 °C密度
8800 kg/m³酸化数
0, +1, +2, +3電気陰性度（Pauling）
1.23第1イオン化エネルギー
6.0215 eV発見年
1878原子半径
175 pm詳細
Holmium is a lanthanide metal and one of the heavy rare earth elements. In compounds it is almost always trivalent, forming Ho³⁺ salts with the pink, yellow, or pale colors typical of f-electron transitions. Natural holmium is monoisotopic, consisting essentially of stable ¹⁶⁵Ho. Its large magnetic moment gives the element and some of its compounds unusual magnetic behavior at low temperature.
Pure holmium has a metallic to bright silver luster. It is relatively soft and malleable and is stable in dry air at room temperature but rapidly oxidizes in moist air and at elevated temperatures. The metal has unusual magnetic properties. Few uses have yet been found for the element. The element, as with other rare earths, seems to have a low acute toxic rating.
The name derives from the Latin holmia for Stockholm. It was discovered in erbia earth by the Swiss chemist J. L. Soret in 1878, who referred to it as element X. It was later independently discovered by the Swedish chemist Per Theodor Cleve in 1879. It was first isolated in 1911 by Homberg, who proposed the name holmium either to recognize the discoverer Per Cleve, who was from Stockholm, or perhaps to establish his own name in history.
Holmium was discovered by Per Theodor Cleve, a Swedish chemist, in 1879. Cleve used the same method Carl Gustaf Mosander used to discover lanthanum, erbium and terbium, he looked for impurities in the oxides of other rare earth elements. He started with erbia, the oxide of erbium (Er2O3), and removed all of the known contaminants. After further processing, he obtained two new materials, one brown and the other green. Cleve named the brown material holmia and the green material thulia. Holmia is the oxide of the element holmium and thulia is the oxide of the element thulium. Holmium's absorption spectrum was observed earlier that year by J. L. Soret and M. Delafontaine, Swiss chemists. Today, holmium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements that can contain as much as 0.05% holmium. Holmium has no commercial applications, although it has unusual magnetic properties that could be exploited in the future.
Holmium forms no commercially important compounds. Some of holmium's compounds include: holmium oxide (Ho2O3), holmium fluoride (HoF3) and holmium iodide (HoI3).
From the Latin word Holmia meaning Stockholm. The special absorption bands of holmium were noticed in 1878 by the Swiss chemists Delafontaine and Soret, who announced the existence of an "Element X." Cleve, of Sweden, later independently discovered the element while working on erbia earth. The element is named after Cleve's native city. Holmia, the yellow oxide, was prepared by Homberg in 1911. Holmium occurs in gadolinite, monazite, and in other rare-earth minerals. It is commercially obtained from monazite, occurring in that mineral to the extent of about 0.05%. It has been isolated by the reduction of its anhydrous chloride or fluoride with calcium metal.
Pure holmium is a soft, silvery, metallic solid that can be cut and worked when freshly prepared. It tarnishes slowly in air and is more reactive as filings or powder. Like other lanthanides, it has a high melting point and a close-packed metallic structure under ordinary conditions.
Holmium has specialized uses rather than large-volume applications. Holmium-doped yttrium aluminium garnet, Y₃Al₅O₁₂, is used in solid-state lasers emitting near 2.1 micrometres, including surgical and materials-processing systems. Holmium oxide, Ho₂O₃, is used as a colorant for glass and cubic zirconia and as a wavelength calibration material in optical spectrophotometry. Metallic holmium and holmium-containing alloys are also used in magnetic research and in some high-field magnet pole pieces.
It has very few practical applications; however, it has some unusual magnetic properties that offer some hope for future applications.
Isotopes in Medicine
Radiosynovectomy with 166Ho-radiopharmaceutical agents can be used for treatment of arthritis. The half-life of 166Ho is 1.1 days. 166Ho ferric hydroxide macroaggregate ([ 166Ho] FHMA) radiosynovectomy is being used because FHMA minimizes extra-articular (outside a joint) leakage of the radioisotope [472] S. Zeisler, K. Weber. J. Radioanal. Nucl. Chem.227, 105 (1998)., [473] O. T. Mäkelä, M. J. Lammi, H. Uusitalo, M. M. Hyttinen, E. Vuorio, H. J. Helminen, R. M. Tulamo. Ann. Rheum. Dis.62, 43 (2003).. 166Ho has been used for radioimmunotherapy (RIT) with labeled antibodies [474] H. Mohsin, F. Jia, G. Sivaguru, M. J. Hudson, T. D. Shelton, T. J. Hoffman, C. S. Cutler, A. R. Ketring, P. S. Athey, J. Simon, R. K. Frank, S. S. Jurisson, M. R. Lewis. Bioconjugate Chem.17, 485 (2006).. The 166Ho-chitosan complex (a linear polysaccharide, which is a long-chain molecule like cellulose that is used by the body for energy storage) is being used for hepatic (liver) cancer therapy [475] M. L. Smits, J. F. Nijsen, M. A. van den Bosch, M. G. Lam, M. A. Vente, J. E. Huijbregts, A. D. van het Schip, M. Elschot, W. Bult, H. W. de Jong, P. C. Meulenhoff, B. A. Zonnenberg. J. Exp. Clin. Cancer Res.29, 70 (2010).. 166Ho-labeled radiopharmaceuticals have been used for alleviating pain from bone metastases [443] International Atomic Energy Agency. Optimization of Production and Quality Control of Therapeutic Radionuclides and Radiopharmaceuticals, IAEA-TECDOC-1114, IAEA VIENNA (1999)., [473] O. T. Mäkelä, M. J. Lammi, H. Uusitalo, M. M. Hyttinen, E. Vuorio, H. J. Helminen, R. M. Tulamo. Ann. Rheum. Dis.62, 43 (2003)., [476] F. Melichar, M. Kropacek, M. Mirzajevova. J. Label. Compd. Radiopharm.46 (S1), S303 (2003). https://onlinelibrary.wiley.com/doi/abs/10.1002/jlcr.772..
166Ho microspheres have been used for intra-arterial radioembolization (treatment where radioactive particles are delivered to a tumor through the bloodstream) of liver metastases (Fig. IUPAC.67.1) [475] M. L. Smits, J. F. Nijsen, M. A. van den Bosch, M. G. Lam, M. A. Vente, J. E. Huijbregts, A. D. van het Schip, M. Elschot, W. Bult, H. W. de Jong, P. C. Meulenhoff, B. A. Zonnenberg. J. Exp. Clin. Cancer Res.29, 70 (2010).. 166Ho is paramagnetic and emits both beta and gamma radiation, which makes it ideal for radioembolization. These properties also enable the distribution of 166Ho microspheres to be visualized with magnetic resonance imaging and single-photon emission computed tomography (SPECT) [475] M. L. Smits, J. F. Nijsen, M. A. van den Bosch, M. G. Lam, M. A. Vente, J. E. Huijbregts, A. D. van het Schip, M. Elschot, W. Bult, H. W. de Jong, P. C. Meulenhoff, B. A. Zonnenberg. J. Exp. Clin. Cancer Res.29, 70 (2010)..
The 166Ho-Patch is a specially designed radioactive skin patch that is used for external radiation of superficial skin cancers and Bowen’s disease in areas that are sensitive and difficult to treat by methods that are more destructive and have poor cosmetic results (i.e. areas of the face) [477] J. D. Lee, K. K. Park, M. G. Lee, E. H. Kim, K. J. Rhim, J. T. Lee, H. S. Yoo, Y. M. Kim, K. B. Park, J. R. Kim. J. Nucl. Med.38, 697 (1997)., [478] Y. L. Chung, J. D. Lee, D. Bang, J. B. Lee, K. B. Park, M. G. Lee. Eur. J. Nucl. Med. Mol. Imaging27, 842 (2000)..
Holmium chemistry is dominated by the +3 oxidation state. Holmium(III) oxide, Ho₂O₃, is the common oxide and is a starting material for many other salts. Holmium(III) chloride, HoCl₃, and holmium(III) nitrate, Ho(NO₃)₃, form hydrated salts that dissolve in water to give Ho³⁺ aquo complexes. The metal reacts with halogens to form trihalides and with acids to produce salts while evolving H₂. Lower oxidation states are not important in ordinary aqueous or solid-state chemistry.
See more information at the Holmium compound page.
Bulk holmium metal has low acute toxicity compared with many industrial metals, but powders and turnings are flammable and can irritate skin, eyes, and lungs. Soluble holmium salts should be handled as toxicologically insufficiently characterized rare-earth compounds. Natural holmium is stable and not a radiological hazard, although neutron activation can produce radioactive isotopes for research or medical studies.
Holmium occurs dispersed in rare-earth minerals such as monazite and xenotime, not as native metal. In weathering environments it behaves like other trivalent lanthanides, tending to bind to phosphates, carbonates, oxides, and clay surfaces rather than remaining highly mobile as a free ion. It has no known essential biological role, and environmental concentrations are normally very low except near rare-earth mining, processing, or waste streams.
Holmium is obtained as a minor by-product of rare-earth extraction, especially from heavy-rare-earth concentrates derived from ion-adsorption clays, xenotime, and some monazite sources. Separation depends on solvent extraction or ion-exchange methods because adjacent lanthanides have very similar chemistry. Demand is small and specialized, so supply is tied to broader rare-earth processing capacity rather than to dedicated holmium mining. Recycling is limited because most uses contain small dispersed amounts.
Occurs in gadolinite. Most often from monazite which is often 50% rare earth and typically 0.05% holmium.
Holmium is a rare cosmic element. Its stable isotope is produced mainly by slow and rapid neutron-capture processes in evolved stars and explosive stellar events, followed by radioactive decay chains that end at stable nuclei. In the Solar System it is concentrated with other refractory lithophile rare earths in rocky material and is depleted in volatile-rich reservoirs only by dilution, not by volatility.
- Holmium has one of the largest magnetic moments of any naturally occurring element.
- Its name comes from Holmia, the Latin name for Stockholm.
- Natural holmium is essentially all ¹⁶⁵Ho.
- Holmium oxide solutions and glasses give sharp optical absorption bands useful for calibration.
- The element was identified spectroscopically before it was isolated in relatively pure form.
画像
性質
物理的性質
- 原子半径（経験値）
- 175 pm 全元素の原子半径（経験値）を比較 →
- 共有結合半径
- 192 pm 全元素の共有結合半径を比較 →
- ファンデルワールス半径
- 216 pm 全元素のファンデルワールス半径を比較 →
- 密度
- 8800 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.0187 L/mol
- 標準温度・圧力（STP）での相
- 固体 全元素の標準温度・圧力（STP）での相を比較 →
- 融点
- 1473.85 °C 全元素の融点を比較 →
- 沸点
- 2699.85 °C 全元素の沸点を比較 →
- 比熱容量
- 0.165 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 27.15 J/(mol·K) 全元素のモル熱容量を比較 →
- 結晶構造
- 六方最密充填構造 全元素の結晶構造を比較 →
化学的性質
- 電気陰性度（Pauling）
- 1.23 全元素の電気陰性度（Pauling）を比較 →
- 電子親和力
- 0.338 eV
- 第1イオン化エネルギー
- 6.0215 eV 全元素の第1イオン化エネルギーを比較 →
- 第2イオン化エネルギー
- 11.781041 eV 全元素の第2イオン化エネルギーを比較 →
- 第3イオン化エネルギー
- 22.790078 eV 全元素の第3イオン化エネルギーを比較 →
- 第4イオン化エネルギー
- 42.520146 eV 全元素の第4イオン化エネルギーを比較 →
- 第5イオン化エネルギー
- 63.90022 eV 全元素の第5イオン化エネルギーを比較 →
- 酸化数
- 0, +1, +2, +3 全元素の酸化数を比較 →
- 価電子
- 3 全元素の価電子を比較 →
- 電子配置
- [Xe] 6s2 4f11
熱力学的性質
- 融解熱
- 0.11608022 eV 全元素の融解熱を比較 →
- 蒸発熱
- 2.591076 eV 全元素の蒸発熱を比較 →
- 昇華熱
- 3.119656 eV
- 原子化熱
- 3.119656 eV
- 原子化エンタルピー
- 3.11551 eV
原子核
- 陽子数
- 67 全元素の陽子数を比較 →
- 中性子数
- 98 全元素の中性子数を比較 →
- 既知の同位体
- 39 全元素の既知の同位体を比較 →
- 安定同位体
- 1 全元素の安定同位体を比較 →
- 最も安定な同位体
- Ho-165
- 発見年
- 1878
存在度
- 存在度（地殻）
- 1.3 mg/kg 全元素の存在度（地殻）を比較 →
- 存在度（海洋）
- 2.2 × 10−7 mg/L 全元素の存在度（海洋）を比較 →
結晶構造
- 格子定数a
- 358 pm
電子構造
- 各電子殻の電子数
- 2, 8, 18, 29, 8, 2 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 7440-60-0 全元素のCAS登録番号を比較 →
- 項記号
- 4I°15/2
- InChI
- InChI=1S/Ho
- InChI Key
- KJZYNXUDTRRSPN-UHFFFAOYSA-N
電子配置 測定値
Ho: 4f¹¹ 6s²[Xe] 4f¹¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹¹ 6s²原子モデル
同位体によって中性子数、質量、安定性は変わりますが、中性原子の電子配置は変わりません。
模式的な原子モデルです。実際の縮尺とは異なります。
原子の指紋
発光／吸収スペクトル
同位体分布
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 |
|---|---|---|---|
| 165 安定 | 164.9303288 ± 0.0000021 | 100.0000% | 安定 |
相／状態
理由: 融点（1473.85 °C）より1448.8 °C低い
模式図、実際の縮尺とは異なります
相転移点
相転移エネルギー
融点で1 molを融解させるのに必要なエネルギー
沸点で1 molを蒸発させるのに必要なエネルギー
昇華点で1 molを昇華させるのに必要なエネルギー
密度
標準条件下
標準条件下
原子スペクトル
全67件中10件を表示しています。 イオンの電荷の昇順で並べています。
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| Ho I | 0 | 234 |
| Ho II | +1 | 55 |
| Ho III | +2 | 126 |
| Ho IV | +3 | 21 |
| Ho V | +4 | 2 |
| Ho VI | +5 | 2 |
| Ho VII | +6 | 2 |
| Ho VIII | +7 | 2 |
| Ho IX | +8 | 2 |
| Ho X | +9 | 2 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| +3 | 6 | データなし | 90.10000000000001 pm |
| +3 | 8 | データなし | 101.49999999999999 pm |
| +3 | 9 | データなし | 107.2 pm |
| +3 | 10 | データなし | 112.00000000000001 pm |
化合物
同位体 (1)
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 165 安定 | 164.9303288 ± 0.0000021 | 100.0000% | 安定 | stable |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 166 pm
- 共有結合半径（Pyykkö、二重結合）
- 133 pm
ファンデルワールス半径
- Alvarez
- 281 pm
- UFF
- 340.9 pm
- MM3
- 267 pm
原子半径と金属半径
- 原子半径（Rahm）
- 273 pm
番号付けの尺度
- Mendeleev
- 33
- Pettifor
- 24
- Glawe
- 23
電気陰性度の尺度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
分極率と分散
- 双極子分極率
- 156 a.u.
- 双極子分極率（不確かさ）
- 10 a.u.
- C₆ (Gould–Bučko)
- 2280 Ha·Bohr6
ミーデマパラメータ
- ミーデマモル体積
- 18.76 cm3/mol
- ミーデマ電子密度
- 2
供給リスクと経済性
- 生産集中度
- 97
- 相対供給リスク
- 10
- 埋蔵量の分布
- 50
- 政治的安定性（最大生産国）
- 24
- 政治的安定性（最大埋蔵国）
- 24
相転移と同素体
| 融点 | 1745.15 K |
| 沸点 | 2973.15 K |
酸化数の分類
専門参考データ
遮蔽定数 (13)
| n | 軌道 | σ |
|---|---|---|
| 1 | s | 1.3088 |
| 2 | p | 4.3332 |
| 2 | s | 17.5444 |
| 3 | d | 13.6531 |
| 3 | p | 20.2546 |
| 3 | s | 20.7649 |
| 4 | d | 35.3284 |
| 4 | f | 39.5304 |
| 4 | p | 32.4372 |
| 4 | s | 31.688 |
結晶半径の詳細 (4)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| 3 | VI | 104.1 | from r^3 vs V plots, | |
| 3 | VIII | 115.5 | from r^3 vs V plots, | |
| 3 | IX | 121.2 | from r^3 vs V plots, | |
| 3 | X | 126 |
同位体の崩壊形式 (57)
| 同位体 | モード | 強度 |
|---|---|---|
| 140 | p | — |
| 140 | B+ | — |
| 140 | B+p | — |
| 141 | p | 100% |
| 141 | B+ | — |
| 141 | B+p | — |
| 142 | B+ | 100% |
| 142 | B+p | — |
| 142 | p | 0% |
| 143 | B+ | — |
X線散乱因子 (514)
| エネルギー (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0.16762 |
| 10.1617 | — | 0.17164 |
| 10.3261 | — | 0.17576 |
| 10.4931 | — | 0.17997 |
| 10.6628 | — | 0.18429 |
| 10.8353 | — | 0.1887 |
| 11.0106 | — | 0.19366 |
| 11.1886 | — | 0.20086 |
| 11.3696 | — | 0.20833 |
| 11.5535 | — | 0.21608 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
1.3 milligrams per kilogram
参考文献 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
2.2×10-7 milligrams per liter
参考文献 (1)
参考文献
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Holmium.
The element property data was retrieved from publications.