Hafnium (Hf)
transition-metalSolid
Peso atomico standard
178,49 uConfigurazione elettronica
[Xe] 6s2 4f14 5d2Punto di fusione
2232,85 °CPunto di ebollizione
4602,85 °CDensità
1,33e+4 kg/m³Stati di ossidazione
−2, 0, +1, +2, +3, +4Elettronegatività (Pauling)
1,3Energia di ionizzazione (1ª)
6,82507 eVAnno della scoperta
1911Raggio atomico
155 pmDettagli
Hafnium is a dense, corrosion-resistant transition metal in group 4, chemically close to zirconium. It occurs almost entirely with zirconium minerals and is difficult to separate because the two elements have similar ionic sizes and chemistry. A defining technological feature is its very large thermal-neutron absorption cross section, which contrasts with zirconium's low absorption and makes high-purity separation important for nuclear applications.
Hafnium is a ductile metal with a brilliant silver luster. Its properties are considerably influenced by presence of zirconium impurities. Of all the elements, zirconium and hafnium are two of the most difficult to separate. Although their chemistry is almost identical, the density of zirconium is about half of hafnium. Very pure hafnium has been produced, with zirconium being the major impurity.
Hafnium has been successfully alloyed with iron, titanium, niobium, tantalum, and other metals. Hafnium carbide is the most refractory binary composition known, and the nitride is the most refractory of all known metal nitrides (m.p. 3310C). At 700 degrees C hafnium rapidly absorbs hydrogen to form the composition HfH1.86.
Hafnium is resistant to concentrated alkalis, but at elevated temperatures reacts with oxygen, nitrogen, carbon, boron, sulfur, and silicon. Halogens react directly to form tetrahalides.
The name derives from the Latin hafnia for Copenhagen. An element named celtium was erroneously claimed to have been discovered in 1911 by the French chemist Georges Urbain in rare earth samples, until the Danish physicist Niels Bohr, predicted hafnium's properties using his theory of electronic configuration of the elements. Bohr argued that hafnium would not be a rare earth element, but would be found in zirconium ore. Hafnium was discovered by the Dutch physicist Dirk Coster and the Hungarian physicist George von Hevesy in 1923, while working at Bohr's Institute in Copenhagen.
Hafnium was discovered by Dirk Coster, a Danish chemist, and George Charles de Hevesy, a Hungarian chemist, in 1923. They used a method known as X-ray spectroscopy to study the arrangement of the outer electrons of atoms in samples of zirconium ore. The electron structure of hafnium had been predicted by Niels Bohr and Coster and Hevesy found a pattern that matched. Hafnium is difficult to separate from zirconium and is present in all of its ores. It is obtained with the same methods used to extract zirconium.
From Hafinia, the Latin name for Copenhagen. Many years before its discovery in 1923 (credited to D. Coster and G. von Hevesey), Hafnium was thought to be present in various minerals and concentrations. On the basis of the Bohr theory, the new element was expected to be associated with zirconium.
It was finally identified in zircon from Norway, by means of X-ray spectroscope analysis. It was named in honor of the city in which the discovery was made. Most zirconium minerals contain 1 to 5 percent hafnium.
It was originally separated from zirconium by repeated recrystallization of the double ammonium or potassium fluorides by von Hevesey and Jantzen. Metallic hafnium was first prepared by van Arkel and deBoer by passing the vapor of the tetraiodide over a heated tungsten filament. Almost all hafnium metal now produced is made by reducing the tetrachloride with magnesium or with sodium (Kroll Process).
Pure hafnium is a lustrous, silvery-gray metal. It is solid and ductile under ordinary conditions and develops a thin protective oxide film in air. Finely divided hafnium can be much more reactive than bulk metal.
Hafnium is used chiefly where neutron absorption or high-temperature stability is valuable. Metallic hafnium is used in control rods and other neutron-absorbing components in some nuclear reactors. Hafnium-containing superalloys and refractory alloys can improve high-temperature strength and oxidation resistance. Hafnium dioxide, HfO₂, is used as a high-k dielectric material in semiconductor devices, replacing or supplementing silicon dioxide in advanced gate stacks. Hafnium compounds also appear in specialty ceramics, optical coatings, and catalysts, but these uses are smaller than zirconium-related industrial chemistry.
Hafnium is a good absorber of neutrons and is used in the control rods of nuclear reactors. Hafnium is also used in vacuum tubes as a getter, a material that combines with and removes trace gases from vacuum tubes. Hafnium has been used as an alloying agent in iron, titanium, niobium and other metals.
Melting near 3890°C, hafnium carbide (HfC) has the highest melting point of any known two-element compound. Hafnium nitride (HfN) also has a high melting point, around 3305°C. Other hafnium compounds include: hafnium chloride (HfCl4), hafnium fluoride (HfF4) and hafnium oxide (HfO2).
Because the element not only has a good absorption cross section for thermal neutrons (almost 600 times that of zirconium), but also excellent mechanical properties and is extremely corrosion-resistant, hafnium is used for reactor control rods. Such rods are used in nuclear submarines.
Hafnium is used in gas-filled and incandescent lamps, and is an efficient getter for scavenging oxygen and nitrogen.
Isotopes in Geochronology
Some 176Hf is radiogenic as a result of it being formed as a product of beta decay of radioactive 176Lu (half-life of 3.73×1010 years) [301] G. Faure. Principles of Isotope Geology, 2nd Edition. p. 608. Wiley, New York (1986).. Thus, relations between the isotope-amount ratiosn(176Hf)/n(177Hf) and n(176Hf)/n(176Lu) have been used to determine the ages of minerals and rocks. Because of the long half-life of 176Lu, these ratios have been used in geochronology studies that document some of the oldest rocks in the Solar System and on Earth (Fig. IUPAC.72.1).
Hafnium isotopic compositions of terrestrial materials evolved differently depending on the relative rates of 176Hf production. Geologists can use calculated lutetium-hafnium ages and the initial isotope-amount ratio n(176Hf)/n(177Hf) along with other isotopic data from the oldest rocks in the Earth to infer that the Earth’s crust differentiated within the first few hundred million years after condensation of the oldest solid matter in the Solar System [502] E. Scherer, C. Münker, K. Mezger. Science293, 683 (2001)..
Radioactive 182Hf decays to 182W with a half-life of 8.9×106 years, which is much less than the age of meteorites and the Earth. Therefore, measurements of the amounts of hafnium and tungsten isotopes in meteorites and terrestrial samples reveal the earlier presence of 182Hf. As a result, this provides information about chemical differentiation and evolution of the early Solar System [503] T. Kleine, M. Touboul, B. Bourdon, F. Nimmo, K. Mezger, H. Palme, S. B. Jacobsen, Q. Z. Yin, A. N. Halliday. Geochim. Cosmochim. Acta73, 5150 (2009)., [504] A. Schersten. Re-Os, Pt-Os and Hf-W Isotopes and Tracing the Core in Mantle Melts, MantlePlumes.org (2014), Feb. 25; http://www.mantleplumes.org/Os-W.html..
Hafnium chemistry is dominated by the +4 oxidation state, reflecting the stable Hf⁴⁺ ion and strong bonding to oxygen, halides, and other hard donor atoms. Hafnium dioxide, HfO₂, is a refractory, chemically durable oxide with high dielectric constant. Hafnium tetrachloride, HfCl₄, is a volatile moisture-sensitive chloride used in purification and chemical vapor or atomic layer deposition chemistry. Organometallic and amide precursors such as tetrakis(dimethylamido)hafnium, Hf[N(CH₃)₂]₄, are important for thin-film deposition. Lower oxidation states exist but are less common and often require specialized conditions.
See more information at the Hafnium compound page.
Bulk hafnium metal is generally of low acute chemical toxicity, but metal dust or powder can ignite and should be treated as a combustible solid. Hafnium compounds vary in hazard; soluble salts, halides, and organometallic precursors may be corrosive, moisture-sensitive, or toxic by inhalation or skin contact. Hafnium is not naturally radioactive in ordinary material, but reactor-exposed hafnium may contain activation products that require radiological control.
Finely divided hafnium is pyrophoric and can ignite spontaneously in air. Care should be taken when machining the metal or when handling hot sponge hafnium.
Hafnium is a trace lithophile element and follows zirconium in igneous rocks, sands, and resistant minerals. It is commonly hosted in zircon, ZrSiO₄, where hafnium substitutes for zirconium. The element has low mobility in most surface environments because its oxides and silicate-hosted forms are sparingly soluble. It has no known biological role, and environmental concentrations are normally controlled by the distribution and weathering resistance of zirconium minerals.
Hafnium is not usually mined as a primary product. It is recovered during the processing of zirconium minerals, especially when nuclear-grade zirconium is purified to remove neutron-absorbing impurities. Separation from zirconium is the central cost and supply constraint, commonly involving solvent extraction or related chemical fractionation followed by conversion to metal or compounds. Demand is concentrated in nuclear control materials, semiconductor precursors, and specialized high-temperature alloys. Supply is therefore tied to zirconium processing capacity and to the need for very low-hafnium zirconium in reactor fuel cladding, rather than to abundant independent hafnium ores.
Obtained from mineral zircon or baddeleyite.
Hafnium is a heavy element made mainly by neutron-capture processes in earlier generations of stars, with contributions from both slow and rapid neutron capture. It is far less abundant cosmically than lighter rock-forming elements. In planetary materials it behaves as a refractory lithophile element, condensing into high-temperature solids and concentrating with zirconium-bearing minerals rather than in metallic cores or volatile phases.
- Hafnium was one of the last stable elements to be identified in nature.
- Its name comes from Hafnia, the Latin name for Copenhagen.
- Zircon can contain enough hafnium to make separation important even when hafnium is not the desired product.
- Hafnium and zirconium are chemically so similar that early analytical work often missed hafnium.
- Hafnium carbide and tantalum hafnium carbide are noted for extremely high melting behavior.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 155 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 175 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 212 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Raggio metallico
- 144 pm Confronta Raggio metallico di tutti gli elementi →
- Densità
- 1,33 × 104 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0136 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 2232,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 4602,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Conducibilità termica
- 23 W/(m·K) Confronta Conducibilità termica di tutti gli elementi →
- Capacità termica specifica
- 0,144 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 25,73 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Esagonale compatta Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 1,3 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 1,16
- Affinità elettronica
- 0,178 eV
- Energia di ionizzazione (1ª)
- 6,82507 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 14,61005 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 22,550078 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 33,370115 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 68,370235 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- −2, 0, +1, +2, +3, +4 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 4 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Xe] 6s2 4f14 5d2
Termodinamiche
- Calore di fusione
- 0,26667358 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 5,959476 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 6,436234 eV
- Calore di atomizzazione
- 6,436234 eV
- Entalpia di atomizzazione
- 6,409286 eV
Nucleari
- Protoni
- 72 Confronta Protoni di tutti gli elementi →
- Neutroni
- 108 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 38 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 4 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Hf-180
- Anno della scoperta
- 1911
Abbondanza
- Abbondanza (crosta terrestre)
- 3 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 7 × 10−6 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 320 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 32, 10, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-58-6 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 3F2
- InChI
- InChI=1S/Hf
- Chiave InChI
- VBJZVLUMGGDVMO-UHFFFAOYSA-N
Configurazione elettronica Misurato
Hf: 4f¹⁴ 5d² 6s²[Xe] 4f¹⁴ 5d² 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d² 6s²Modello atomico
Gli isotopi modificano il numero di neutroni, la massa e la stabilità — non la configurazione elettronica di un atomo neutro.
Modello atomico schematico, non in scala.
Impronta atomica
Spettro di emissione / assorbimento
Distribuzione isotopica
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 176 Stabile | 175,9414076 ± 0,0000022 | 5,2600% | Stabile |
| 178 Stabile | 177,9437058 ± 0,000002 | 27,2800% | Stabile |
| 179 Stabile | 178,9458232 ± 0,000002 | 13,6200% | Stabile |
| 180 Stabile | 179,946557 ± 0,000002 | 35,0800% | Stabile |
Fase / Stato
Motivo: 2207,8 °C sotto il punto di fusione (2232,85 °C)
Schema non in scala
Punti di transizione di fase
Energie di transizione
Energia necessaria per fondere 1 mol al punto di fusione
Energia necessaria per vaporizzare 1 mol al punto di ebollizione
Energia necessaria per sublimare 1 mol al punto di sublimazione
Densità
In condizioni standard
In condizioni standard
Spettri atomici
Sono visualizzati 10 di 72. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Hf I | 0 | 5341 | 187 | 3821 |
| Hf II | +1 | 218 | 2 | 10 |
| Hf III | +2 | 37 | 0 | 0 |
| Hf IV | +3 | 27 | 0 | 0 |
| Hf V | +4 | 82 | 0 | 0 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Hf I | 0 | 333 |
| Hf II | +1 | 125 |
| Hf III | +2 | 2 |
| Hf IV | +3 | 2 |
| Hf V | +4 | 2 |
| Hf VI | +5 | 2 |
| Hf VII | +6 | 2 |
| Hf VIII | +7 | 2 |
| Hf IX | +8 | 2 |
| Hf X | +9 | 2 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +4 | 4 | N/D | 57.99999999999999 pm |
| +4 | 6 | N/D | 71 pm |
| +4 | 7 | N/D | 76 pm |
| +4 | 8 | N/D | 83 pm |
Composti
Isotopi (4)
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 176 Stabile | 175,9414076 ± 0,0000022 | 5,2600% ± 0,0700% | Stabile | stable | |
| 178 Stabile | 177,9437058 ± 0,000002 | 27,2800% ± 0,0700% | Stabile | stable | |
| 179 Stabile | 178,9458232 ± 0,000002 | 13,6200% ± 0,0200% | Stabile | stable | |
| 180 Stabile | 179,946557 ± 0,000002 | 35,0800% ± 0,1600% | Stabile | stable |
Righe spettrali
Sono visualizzati 50 di 1890. Per impostazione predefinita sono mostrate soltanto le righe spettrali con intensità misurata.
| Lunghezza d'onda (nm) | Intensità | Stadio di ionizzazione | Tipo | Transizione | Accuratezza | Fonte | |
|---|---|---|---|---|---|---|---|
| 417.433998 nm | 48000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 380.03629 nm | 36000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 382.072307 nm | 34000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p y 3F* | Misurata | NIST | |
| 723.71003 nm | 34000 | Hf I | emission | 5d2.6s2 a 3F → 5d.6s2.(a 2D).6p z 3D* | Misurata | NIST | |
| 384.917811 nm | 32000 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3F).6s.(a 2F).6p y 1D* | Misurata | NIST | |
| 713.1807 nm | 32000 | Hf I | emission | 5d2.6s2 a 3F → 5d.6s2.(a 2D).6p z 3D* | Misurata | NIST | |
| 389.993003 nm | 29000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 395.181289 nm | 26000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p y 3F* | Misurata | NIST | |
| 385.830632 nm | 25000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p y 3D* | Misurata | NIST | |
| 724.0873 nm | 21000 | Hf I | emission | 5d2.6s2 a 3F → 5d.6s2.(a 2D).6p z 3D* | Misurata | NIST | |
| 393.137246 nm | 19000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p y 3D* | Misurata | NIST | |
| 480.049829 nm | 17000 | Hf I | emission | 5d2.6s2 a 1D → 5d.6s2.(a 2D).6p z 1P* | Misurata | NIST | |
| 397.347912 nm | 15000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 706.38474 nm | 15000 | Hf I | emission | 5d2.6s2 a 1D → 5d.6s2.(a 2D).6p z 3P* | Misurata | NIST | |
| 381.177553 nm | 14000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 3G* | Misurata | NIST | |
| 555.06011 nm | 14000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5G* | Misurata | NIST | |
| 555.211884 nm | 14000 | Hf I | emission | 5d2.6s2 a 1D → 5d.6s2.(a 2D).6p z 1F* | Misurata | NIST | |
| 456.593715 nm | 13000 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3P).6s.(a 4P).6p y 5D* | Misurata | NIST | |
| 435.630591 nm | 12000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 445.734411 nm | 12000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5F* | Misurata | NIST | |
| 459.87979 nm | 12000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5F* | Misurata | NIST | |
| 462.086529 nm | 12000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5F* | Misurata | NIST | |
| 465.518924 nm | 12000 | Hf I | emission | 5d2.6s2 a 3P → 5d2.(a 3P).6s.(a 4P).6p z 3S* | Misurata | NIST | |
| 380.044548 nm | 11000 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3P).6s.(a 4P).6p z 5S* | Misurata | NIST | |
| 429.477692 nm | 11000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 681.89395 nm | 11000 | Hf I | emission | 5d2.6s2 a 3P → 5d.6s2.(a 2D).6p z 1F* | Misurata | NIST | |
| 396.799621 nm | 10000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 406.28356 nm | 10000 | Hf I | emission | 5d.6s2.(a 2D).6p z 1D* → 3512 | Misurata | NIST | |
| 497.525232 nm | 10000 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5F* | Misurata | NIST | |
| 454.093108 nm | 8400 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3F).6s.(a 4F).6p y 3F* | Misurata | NIST | |
| 443.80364 nm | 8300 | Hf I | emission | 5d2.6s2 a 3P → 5d2.(a 3P).6s.(a 4P).6p z 3S* | Misurata | NIST | |
| 446.117576 nm | 8300 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3P).6s.(a 4P).6p z 3S* | Misurata | NIST | |
| 459.891547 nm | 8300 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5D* | Misurata | NIST | |
| 408.33549 nm | 8000 | Hf I | emission | 5d.6s2.(a 2D).6p z 1D* → 3499 | Misurata | NIST | |
| 571.91718 nm | 7300 | Hf I | emission | 5d2.6s2 a 3P → 5d.6s2.(a 2D).6p z 1P* | Misurata | NIST | |
| 403.225898 nm | 7200 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p y 3F* | Misurata | NIST | |
| 478.27405 nm | 7100 | Hf I | emission | 5d.6s2.(a 2D).6p z 3F* → 6p2.(3P).5d.(2D).6s c 3D | Misurata | NIST | |
| 383.001314 nm | 6700 | Hf I | emission | 5d3.(b 4F).6s a 5F → 5d2.(b 1D).6s.(b 2D).6p v 3F* | Misurata | NIST | |
| 504.743848 nm | 6500 | Hf I | emission | 5d2.6s2 a 3P → 5d2.(a 3F).6s.(a 4F).6p y 3D* | Misurata | NIST | |
| 485.92338 nm | 6400 | Hf I | emission | 5d.6s2.(a 2D).6p z 3F* → 3512 | Misurata | NIST | |
| 386.09058 nm | 6300 | Hf I | emission | 5d2.6s2 a 3P → 5d2.(a 3F).6s.(a 2F).6p y 1F* | Misurata | NIST | |
| 441.790242 nm | 6200 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3F).6s.(a 4F).6p y 3D* | Misurata | NIST | |
| 388.935622 nm | 5900 | Hf I | emission | 5d2.6s2 a 1D → 5d2.(a 3P).6s.(a 4P).6p y 5D* | Misurata | NIST | |
| 469.90048 nm | 5900 | Hf I | emission | 5d2.(a 3F).6s.(a 4F).6p z 5G* → 5d2.(3F).6s.(a 4F).7s b 5F | Misurata | NIST | |
| 678.92714 nm | 5900 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5G* | Misurata | NIST | |
| 433.027751 nm | 5800 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p y 3F* | Misurata | NIST | |
| 410.65431 nm | 5600 | Hf I | emission | 5d2.6s2 a 1G → 5d2.(a 3F).6s.(a 2F).6p y 1F* | Misurata | NIST | |
| 426.34428 nm | 5400 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5F* | Misurata | NIST | |
| 477.37157 nm | 5400 | Hf I | emission | 5d2.6s2 a 3P → 5d.6s2.(a 2D).6p z 1P* | Misurata | NIST | |
| 590.29382 nm | 5400 | Hf I | emission | 5d2.6s2 a 3F → 5d2.(a 3F).6s.(a 4F).6p z 5G* | Misurata | NIST |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 152 pm
- Raggio covalente (Pyykkö, legame doppio)
- 128 pm
- Raggio covalente (Pyykkö, legame triplo)
- 122 pm
Raggi di van der Waals
- Batsanov
- 225 pm
- Alvarez
- 263 pm
- UFF
- 314,1 pm
- MM3
- 253 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 264 pm
- Raggio metallico (C12)
- 159 pm
Scale di numerazione
- Mendeleev
- 45
- Pettifor
- 50
- Glawe
- 50
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 4
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 103 a.u.
- Polarizzabilità dipolare (inc.)
- 6 a.u.
- C₆ (Gould–Bučko)
- 1040 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 13,45 cm3/mol
- Densità elettronica di Miedema
- 3
Transizioni di fase e allotropi
| Punto di fusione | 2506,15 K |
| Punto di ebollizione | 4873,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (14)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,3984 |
| 2 | p | 4,4012 |
| 2 | s | 18,8102 |
| 3 | d | 13,5702 |
| 3 | p | 21,0168 |
| 3 | s | 21,6885 |
| 4 | d | 36,476 |
| 4 | f | 39,7904 |
| 4 | p | 34,0704 |
| 4 | s | 33,0228 |
Dettaglio dei raggi cristallini (4)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 4 | IV | 72 | from r^3 vs V plots, | |
| 4 | VI | 85 | from r^3 vs V plots, | |
| 4 | VII | 90 | ||
| 4 | VIII | 97 |
Modalità di decadimento degli isotopi (46)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 153 | B+ | — |
| 154 | B+ | 100% |
| 154 | A | 0% |
| 155 | B+ | 100% |
| 155 | A | — |
| 156 | A | 100% |
| 156 | B+ | — |
| 157 | A | 94% |
| 157 | B+ | 14% |
| 158 | B+ | 55,7% |
Fattori di diffusione dei raggi X (514)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 2,62338 |
| 10,1617 | — | 2,71485 |
| 10,3261 | — | 2,80951 |
| 10,4931 | — | 2,90326 |
| 10,6628 | — | 2,98247 |
| 10,8353 | — | 3,06384 |
| 11,0106 | — | 3,14744 |
| 11,1886 | — | 3,21346 |
| 11,3696 | — | 3,27509 |
| 11,5535 | — | 3,33789 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3.0 milligrams per kilogram
Riferimenti (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
7×10-6 milligrams per liter
Riferimenti (1)
Riferimenti
(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 Hafnium.
The element property data was retrieved from publications.