Gadolinium (Gd)
lanthanideSolid
मानक परमाणु भार
157.25 uइलेक्ट्रॉन विन्यास
[Xe] 6s2 4f7 5d1गलनांक
1312.85 °Cक्वथनांक
3272.85 °Cघनत्व
7900 kg/m³ऑक्सीकरण अवस्थाएँ
0, +1, +2, +3विद्युतऋणात्मकता (पॉलिंग)
1.2आयनन ऊर्जा (प्रथम)
6.1498 eVखोज का वर्ष
1886परमाणु त्रिज्या
180 pmविवरण
Gadolinium is a silvery lanthanide metal and one of the middle rare-earth elements. Its chemistry is dominated by the +3 oxidation state, but its seven unpaired 4f electrons give it unusually strong magnetic behavior for a rare-earth element. Natural gadolinium is a mixture of stable isotopes, with ¹⁵²Gd very long-lived and weakly radioactive. The element is technologically important in magnetic materials, neutron absorption, phosphors, and medical contrast agents.
As with other related rare-earth metals, gadolinium is silvery white, has a metallic luster, and is malleable and ductile. At room temperature, gadolinium crystallizes in the hexagonal, close-packed alpha form. Upon heating to 1235°C, alpha gadolinium transforms into the beta form, which has a body-centered cubic structure.
The metal is relatively stable in dry air, but tarnishes in moist air and forms a loosely adhering oxide film which falls off and exposes more surface to oxidation. The metal reacts slowly with water and is soluble in dilute acid.
Gadolinium has the highest thermal neutron capture cross-section of any known element (49,000 barns).
The name derives from the mineral gadolinite, in which it was found, and that had been named for the Finnish rare earth chemist Johan Gadolin. Gadolinium was discovered by the Swiss chemist Jean-Charles Galissard de Marignac in 1886, who produced a white oxide in a samarskite mineral. In 1886, the French chemist Paul-Emile Lecoq de Boisbaudran gave the name gadolinium.
Spectroscopic evidence for the existence of gadolinium was first observed by the Swiss chemist Jean Charles Galissard de Marignac in the minerals didymia and gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10) in 1880. Today, gadolinium is primarily obtained from the minerals monazite ((Ce, La, Th, Nd, Y)PO4) and bastnasite ((Ce,La,Y)CO3F).
From gadolinite, a mineral named for Gadolin, a Finnish chemist. The rare earth metal is obtained from the mineral gadolinite. Gadolinia, the oxide of gadolinium, was separated by Marignac in 1880 and Lecoq de Boisbaudran independently isolated it from Mosander's yttria in 1886.
Pure gadolinium is a soft, bright, silvery-white metal when freshly cut. It tarnishes in air and can form a darker oxide surface. At ordinary pressure it is ferromagnetic below about 20 °C, close enough to room temperature that modest temperature changes strongly affect its magnetism.
Gadolinium is used where high magnetic moment or high neutron-capture ability is valuable. Gadolinium compounds are used in some magnetic resonance imaging contrast agents, where chelation is essential to control toxicity. Gadolinium oxide is used in phosphors and scintillators, and gadolinium gallium garnet has served as a substrate and optical material. Gadolinium is also used in control materials and burnable neutron absorbers in some nuclear reactors, often as gadolinium oxide mixed into fuel.
Gadolinium has the greatest ability to capture thermal neutrons of all known elements and can be used as control rods for nuclear reactors. Unfortunately, the two isotopes best suited for neutron capture, gadolinium-155 and gadolinium-157, are present in gadolinium in small amounts. As a result, gadolinium control rods quickly lose their effectiveness.
Gadolinium can be combined with yttrium to form garnets that have applications in microwave technology. Gadolinium can be alloyed with iron, chromium and other metals to improve their workability and their resistance to high temperatures and oxidation. Gadolinium compounds are used to make phosphors for color televisions.
Gadolinium yttrium garnets are used in microwave applications and gadolinium compounds are used as phosphors in color television sets.
The metal has unusual superconductive properties. As little as 1 percent gadolinium improves the workability and resistance of iron, chromium, and related alloys to high temperatures and oxidation.
Gadolinium ethyl sulfate has extremely low noise characteristics and may find use in duplicating the performance of amplifiers, such as the maser.
The metal is ferromagnetic. Gadolinium is unique for its high magnetic movement and for its special Curie temperature (above which ferromagnetism vanishes) lying just at room temperature, meaning it could be used as a magnetic component that can sense hot and cold.
Isotopes in Earth/Planetary Science
The lunar surface is continuously exposed to cosmic radiation, and the interaction between planetary material and cosmic rays produces secondary neutrons. The neutron flux can be investigated using the large neutron capture cross sections of 149Sm, 155Gd, and 157Gd. For example, 157Gd will absorb neutrons and be converted to 158Gd. On a cross plot of n(158Gd)/n(160Gd) isotope-amount ratio and n(157Gd)/n(160Gd) isotope-amount ratio (Fig. IUPAC.64.1), values will move from the lower right corner to the upper left corner of the cross plot with increasing time or increasing flux.
Isotopes in Medicine
The addition of 157Gd to Neutron Capture Therapy (NCT) has been shown to be more effective at targeting tumors than the previous method of using only 10B for the treatment (Fig. IUPAC.64.2) [453] C. N. Culbertson, T. Jevremovic. Phys. Med. Biol.48, 3943 (2003).. 153Gd (with a half-life of 0.66 years) is used in the production of photon line sources (an optical source that emits one or more spectrally narrow lines as opposed to a continuous spectrum) to manufacture 153Gd line sources [454] V. M. Lebedev, J. N. Gordeev, E. A. Karelin, V. D. Gavrilov. Appl. Radiat. Isot.53, 829 (2000).. 153Gd is also used as a photon source of the dual-photon absorptiometry (DPA) technique that is used to measure bone mineral content (BMC). Studies for this technique have been conducted in horses and humans [455] A. Moure, P. Reichmann, H. R. Gamba. Phys. Med. Biol.48, 3851 (2003)., [456] P. Tothill, M. A. Smith, D. Sutton. Br. J. Radiol.56, 829 (1983)..
Gadolinium chemistry is mainly that of Gd³⁺ salts and oxides. Gadolinium(III) oxide, Gd₂O₃, is a stable refractory oxide and a common starting material. Gadolinium(III) chloride, GdCl₃, and gadolinium(III) nitrate, Gd(NO₃)₃, form hydrated salts and coordination complexes. Gadolinium(III) sulfate, Gd₂(SO₄)₃, and many organic chelates are also important. The +2 state is known in specialized solid-state and organometallic chemistry, but it is not the normal aqueous form.
See more information at the Gadolinium compound page.
Metallic gadolinium dust can burn and should be treated as a reactive metal powder. Soluble gadolinium salts are toxic at sufficient dose, largely because free Gd³⁺ can interfere with calcium-dependent biological processes. Medical contrast agents use tightly bound complexes, but release or retention of gadolinium is a recognized safety concern, especially in vulnerable patients. Stable gadolinium isotopes do not present a radiological hazard of practical importance.
Gadolinium occurs in nature dispersed with other rare-earth elements in minerals such as monazite and bastnäsite. It is not known to have an essential biological role. In soils and waters it tends to bind strongly to minerals, phosphates, carbonates, and organic matter rather than remain as a simple free ion. Anthropogenic gadolinium from contrast agents can pass through wastewater systems and has been detected as anomalous rare-earth patterns in some surface waters.
Gadolinium is not mined as a primary metal. It is recovered during processing of rare-earth ores, with separation from chemically similar lanthanides by solvent extraction or ion-exchange methods. Supply depends on the rare-earth industry as a whole and on the economics of separating mixed concentrates into individual oxides. Demand is smaller than for neodymium or cerium but important in medical imaging, nuclear technology, phosphors, and specialty magnetic materials. Recycling is limited and is most practical from concentrated industrial scrap rather than diffuse medical releases.
Gadolinium is found in several other minerals, including monazite and bastnasite, both of which are commercially important. With the development of ion-exchange and solvent extraction techniques, the availability and prices of gadolinium and the other rare-earth metals have greatly improved. The metal can be prepared by the reduction of the anhydrous fluoride with metallic calcium.
Gadolinium is a heavy element made mainly by neutron-capture processes in earlier generations of stars. Its stable isotopes include products associated with both slow and rapid neutron capture. In the Solar System it is far less abundant than iron or the light elements, but it follows the general rare-earth pattern in meteorites and planetary materials.
- Natural gadolinium has one of the highest thermal-neutron absorption capacities among stable-element mixtures.
- The element is named through gadolinite, a mineral ultimately named for Johan Gadolin.
- Gadolinium becomes ferromagnetic only just below ordinary room temperature.
- Free Gd³⁺ is far more hazardous than gadolinium held in approved chelating ligands.
- Gadolinium anomalies in rivers can trace releases from medical imaging agents.
चित्र
गुण
भौतिक
- परमाणु त्रिज्या (आनुभविक)
- 180 pm सभी तत्वों की परमाणु त्रिज्या (आनुभविक) की तुलना करें →
- सहसंयोजक त्रिज्या
- 196 pm सभी तत्वों की सहसंयोजक त्रिज्या की तुलना करें →
- वान डर वाल्स त्रिज्या
- 237 pm सभी तत्वों की वान डर वाल्स त्रिज्या की तुलना करें →
- घनत्व
- 7900 kg/m³ सभी तत्वों की घनत्व की तुलना करें →
- मोलर आयतन
- 0.0199 L/mol
- STP पर प्रावस्था
- ठोस सभी तत्वों की STP पर प्रावस्था की तुलना करें →
- गलनांक
- 1312.85 °C सभी तत्वों की गलनांक की तुलना करें →
- क्वथनांक
- 3272.85 °C सभी तत्वों की क्वथनांक की तुलना करें →
- विशिष्ट ऊष्मा धारिता
- 0.236 J/(g·K) सभी तत्वों की विशिष्ट ऊष्मा धारिता की तुलना करें →
- मोलर ऊष्मा धारिता
- 37.03 J/(mol·K) सभी तत्वों की मोलर ऊष्मा धारिता की तुलना करें →
- क्रिस्टल संरचना
- षट्कोणीय सघन संकुलित सभी तत्वों की क्रिस्टल संरचना की तुलना करें →
रासायनिक
- विद्युतऋणात्मकता (पॉलिंग)
- 1.2 सभी तत्वों की विद्युतऋणात्मकता (पॉलिंग) की तुलना करें →
- इलेक्ट्रॉन बंधुता
- 0.132 eV
- आयनन ऊर्जा (प्रथम)
- 6.1498 eV सभी तत्वों की आयनन ऊर्जा (प्रथम) की तुलना करें →
- आयनन ऊर्जा (द्वितीय)
- 12.076042 eV सभी तत्वों की आयनन ऊर्जा (द्वितीय) की तुलना करें →
- आयनन ऊर्जा (तृतीय)
- 20.540071 eV सभी तत्वों की आयनन ऊर्जा (तृतीय) की तुलना करें →
- आयनन ऊर्जा (चतुर्थ)
- 44.440153 eV सभी तत्वों की आयनन ऊर्जा (चतुर्थ) की तुलना करें →
- आयनन ऊर्जा (पंचम)
- 64.800223 eV सभी तत्वों की आयनन ऊर्जा (पंचम) की तुलना करें →
- ऑक्सीकरण अवस्थाएँ
- 0, +1, +2, +3 सभी तत्वों की ऑक्सीकरण अवस्थाएँ की तुलना करें →
- संयोजकता इलेक्ट्रॉन
- 3 सभी तत्वों की संयोजकता इलेक्ट्रॉन की तुलना करें →
- इलेक्ट्रॉन विन्यास
- [Xe] 6s2 4f7 5d1
ऊष्मागतिक
- गलन ऊष्मा
- 0.10364305 eV सभी तत्वों की गलन ऊष्मा की तुलना करें →
- वाष्पन ऊष्मा
- 3.109292 eV सभी तत्वों की वाष्पन ऊष्मा की तुलना करें →
- ऊर्ध्वपातन ऊष्मा
- 4.124994 eV
- परमाणुकरण ऊष्मा
- 4.124994 eV
- परमाणुकरण एन्थैल्पी
- 4.119811 eV
नाभिकीय
- प्रोटॉन
- 64 सभी तत्वों की प्रोटॉन की तुलना करें →
- न्यूट्रॉन
- 94 सभी तत्वों की न्यूट्रॉन की तुलना करें →
- ज्ञात समस्थानिक
- 40 सभी तत्वों की ज्ञात समस्थानिक की तुलना करें →
- स्थिर समस्थानिक
- 5 सभी तत्वों की स्थिर समस्थानिक की तुलना करें →
- सबसे स्थिर समस्थानिक
- Gd-158
- खोज का वर्ष
- 1886
प्रचुरता
- प्रचुरता (भूपर्पटी)
- 6.2 mg/kg सभी तत्वों की प्रचुरता (भूपर्पटी) की तुलना करें →
- प्रचुरता (महासागर)
- 7 × 10−7 mg/L सभी तत्वों की प्रचुरता (महासागर) की तुलना करें →
क्रिस्टल संरचना
- जालक स्थिरांक a
- 364 pm
इलेक्ट्रॉनिक संरचना
- प्रति कोश इलेक्ट्रॉन
- 2, 8, 18, 25, 9, 2 सभी तत्वों की प्रति कोश इलेक्ट्रॉन की तुलना करें →
पहचानकर्ता
- CAS संख्या
- 7440-54-2 सभी तत्वों की CAS संख्या की तुलना करें →
- टर्म प्रतीक
- 9D°2
- InChI
- InChI=1S/Gd
- InChI कुंजी
- UIWYJDYFSGRHKR-UHFFFAOYSA-N
इलेक्ट्रॉन विन्यास मापित
Gd: 4f⁷ 5d¹ 6s²[Xe] 4f⁷ 5d¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 5d¹ 6s²परमाणु मॉडल
समस्थानिक न्यूट्रॉन की संख्या, द्रव्यमान और स्थिरता बदलते हैं — उदासीन परमाणु का इलेक्ट्रॉन विन्यास नहीं।
सांकेतिक परमाणु मॉडल, वास्तविक अनुपात में नहीं।
परमाणु पहचान-चिह्न
उत्सर्जन / अवशोषण स्पेक्ट्रम
समस्थानिक वितरण
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु |
|---|---|---|---|
| 154 स्थिर | 153.9208741 ± 0.0000017 | 2.1800% | स्थिर |
| 155 स्थिर | 154.9226305 ± 0.0000017 | 14.8000% | स्थिर |
| 156 स्थिर | 155.9221312 ± 0.0000017 | 20.4700% | स्थिर |
| 157 स्थिर | 156.9239686 ± 0.0000017 | 15.6500% | स्थिर |
| 158 स्थिर | 157.9241123 ± 0.0000017 | 24.8400% | स्थिर |
प्रावस्था / अवस्था
कारण: गलनांक (1312.85 °C) से 1287.8 °C कम
सांकेतिक, वास्तविक अनुपात में नहीं
प्रावस्था संक्रमण बिंदु
संक्रमण ऊर्जाएँ
गलनांक पर 1 mol को पिघलाने के लिए आवश्यक ऊर्जा
क्वथनांक पर 1 mol को वाष्पित करने के लिए आवश्यक ऊर्जा
ऊर्ध्वपातनांक पर 1 mol के ऊर्ध्वपातन के लिए आवश्यक ऊर्जा
घनत्व
मानक परिस्थितियों में
मानक परिस्थितियों में
परमाणु स्पेक्ट्रम
64 में से 10 दिखाए जा रहे हैं। आयन के आवेश के अनुसार आरोही क्रम में व्यवस्थित।
उपलब्ध स्पेक्ट्रमी रेखा डेटा ?
| आयन | आवेश | कुल रेखाएँ | संक्रमण प्रायिकताएँ | स्तर पदनाम |
|---|---|---|---|---|
| Gd I | 0 | 371 | 16 | 19 |
| Gd II | +1 | 465 | 0 | 17 |
| Gd III | +2 | 158 | 0 | 0 |
| Gd IV | +3 | 50 | 0 | 0 |
उपलब्ध ऊर्जा स्तर डेटा ?
| आयन | आवेश | स्तर |
|---|---|---|
| Gd I | 0 | 634 |
| Gd II | +1 | 321 |
| Gd III | +2 | 28 |
| Gd IV | +3 | 5 |
| Gd V | +4 | 2 |
| Gd VI | +5 | 2 |
| Gd VII | +6 | 2 |
| Gd VIII | +7 | 2 |
| Gd IX | +8 | 2 |
| Gd X | +9 | 2 |
आयनिक त्रिज्याएँ
| आवेश | उपसहसंयोजन | प्रचक्रण | त्रिज्या |
|---|---|---|---|
| +3 | 6 | उपलब्ध नहीं | 93.8 pm |
| +3 | 7 | उपलब्ध नहीं | 100 pm |
| +3 | 8 | उपलब्ध नहीं | 105.3 pm |
| +3 | 9 | उपलब्ध नहीं | 110.7 pm |
यौगिक
समस्थानिक (5)
Natural gadolinium is a mixture of seven isotopes, but 17 isotopes of gadolinium are now recognized. Although two of these, 155Gd and 157Gd, have excellent capture characteristics, they are only present naturally in low concentrations. As a result, gadolinium has a very fast burnout rate and has limited use as a nuclear control rod material.
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु | क्षय का प्रकार | |
|---|---|---|---|---|---|
| 154 स्थिर | 153.9208741 ± 0.0000017 | 2.1800% ± 0.0300% | स्थिर | stable | |
| 155 स्थिर | 154.9226305 ± 0.0000017 | 14.8000% ± 0.1200% | स्थिर | stable | |
| 156 स्थिर | 155.9221312 ± 0.0000017 | 20.4700% ± 0.0900% | स्थिर | stable | |
| 157 स्थिर | 156.9239686 ± 0.0000017 | 15.6500% ± 0.0200% | स्थिर | stable | |
| 158 स्थिर | 157.9241123 ± 0.0000017 | 24.8400% ± 0.0700% | स्थिर | stable |
विस्तृत गुण
सहसंयोजक त्रिज्याएँ (विस्तृत)
- सहसंयोजक त्रिज्या (प्यूक्को)
- 169 pm
- सहसंयोजक त्रिज्या (प्यूक्को, द्विबंध)
- 135 pm
- सहसंयोजक त्रिज्या (प्यूक्को, त्रिबंध)
- 132 pm
वान डर वाल्स त्रिज्याएँ
- Alvarez
- 283 pm
- UFF
- 336.8 pm
- MM3
- 271 pm
परमाणु और धात्विक त्रिज्याएँ
- परमाणु त्रिज्या (राह्म)
- 277 pm
संख्यांकन मापक्रम
- Mendeleev
- 27
- Pettifor
- 27
- Glawe
- 26
विद्युतऋणात्मकता मापक्रम
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 7
- Robles–Bartolotti
- 6
ध्रुवणीयता और परिक्षेपण
- द्विध्रुव ध्रुवणीयता
- 158 a.u.
- द्विध्रुव ध्रुवणीयता (अनिश्चितता)
- 20 a.u.
- C₆ (Gould–Bučko)
- 2340 Ha·Bohr6
मीडेमा प्राचल
- मीडेमा मोलर आयतन
- 19.9 cm3/mol
- मीडेमा इलेक्ट्रॉन घनत्व
- 2
आपूर्ति जोखिम और अर्थशास्त्र
- उत्पादन संकेंद्रण
- 97
- सापेक्ष आपूर्ति जोखिम
- 10
- भंडार वितरण
- 50
- राजनीतिक स्थिरता (प्रमुख उत्पादक)
- 24
- राजनीतिक स्थिरता (सबसे अधिक भंडार वाला देश)
- 24
प्रावस्था संक्रमण और अपररूप
| गलनांक | 1586.15 K |
| क्वथनांक | 3546.15 K |
ऑक्सीकरण अवस्था की श्रेणियाँ
उन्नत संदर्भ डेटा
परिरक्षण स्थिरांक (13)
| n | कक्षक | σ |
|---|---|---|
| 1 | s | 1.2565 |
| 2 | p | 4.2946 |
| 2 | s | 16.783 |
| 3 | d | 13.723 |
| 3 | p | 19.8508 |
| 3 | s | 20.2903 |
| 4 | d | 34.3664 |
| 4 | f | 38.9864 |
| 4 | p | 31.3532 |
| 4 | s | 30.556 |
क्रिस्टल त्रिज्याओं का विवरण (4)
| आवेश | CN | प्रचक्रण | rcrystal (pm) | उत्पत्ति |
|---|---|---|---|---|
| 3 | VI | 107.8 | from r^3 vs V plots, | |
| 3 | VII | 114 | ||
| 3 | VIII | 119.3 | from r^3 vs V plots, | |
| 3 | IX | 124.7 | from r^3 vs V plots, calculated, |
समस्थानिक क्षय के प्रकार (57)
| समस्थानिक | मोड | तीव्रता |
|---|---|---|
| 133 | B+ | — |
| 133 | B+p | — |
| 134 | B+ | — |
| 134 | B+p | — |
| 135 | B+ | 100% |
| 135 | B+p | 2% |
| 136 | B+ | — |
| 136 | B+p | — |
| 137 | B+ | 100% |
| 137 | B+p | — |
एक्स-रे प्रकीर्णन गुणक (719)
| ऊर्जा (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 2.59886 |
| 10.1152 | — | 2.63957 |
| 10.2317 | — | 2.68119 |
| 10.3496 | — | 2.72415 |
| 10.4688 | — | 2.7678 |
| 10.5894 | — | 2.81214 |
| 10.7114 | — | 2.8572 |
| 10.8348 | — | 2.90298 |
| 10.9596 | — | 2.94949 |
| 11.0859 | — | 2.99675 |
अतिरिक्त डेटा
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
6.2 milligrams per kilogram
संदर्भ (1)
- [5] Gadolinium https://education.jlab.org/itselemental/ele064.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
7×10-7 milligrams per liter
संदर्भ (1)
- [5] Gadolinium https://education.jlab.org/itselemental/ele064.html
Sources
Sources of this element.
Gadolinium is found in several other minerals, including monazite and bastnasite, both of which are commercially important. With the development of ion-exchange and solvent extraction techniques, the availability and prices of gadolinium and the other rare-earth metals have greatly improved. The metal can be prepared by the reduction of the anhydrous fluoride with metallic calcium.
संदर्भ (1)
- [6] Gadolinium https://periodic.lanl.gov/64.shtml
संदर्भ
(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 Gadolinium.
The element property data was retrieved from publications.