Hafnium information, including Technical Data, Safety Data and its high purity properties, research, applications and other useful facts are discussed below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity and thermal properties are included.
 Hafnium is one of the Group IV transition elements that is refined from various zirconic mineral deposits. Hafnium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder.
It's primary uses are due to its ability as a nuclear "getter" or absorber of neutrons. It is a primary component in nuclear control rods for this purpose. It also finds uses as a dopant in the alloy of steel and titanium. It is also used in the production of mantles for high intensity incandescent lamps.
Hafnium is replacing polysilicon as the principle gate or electrode material in metal oxide semiconductor field effect transistors (MOSFETs) which are the basis for all modern semiconductors. As semiconductors have gotten smaller, the limiting factor in further size reduction has been the ability of the silicon oxide gate to perform below 10 angstroms where leakage occurs. Recent research has been devoted to the development of High-k materials which can function as a di-electric barrier or gate with lower leakage. Using hafnium based alloys as this di-electric gate has allowed for the development of MOSFET gates smaller than 10 angstroms. This allows for further size reduction, reduced switching power requirements and improved performance.
Hafnium facts, including appearance, CAS #, and molecular formula and safety data, research and properties are
available for many specific states, forms and shapes on the product pages listed to the left. Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Nanoparticles and nanopowders provide ultra high surface area which nanotechnology research and recent experiments demonstrate function to create new and unique properties and benefits.
 Oxides are available in forms including powders and dense pellets for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Hafnium is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries.
Hafnium is a Block D, Group 4, Period 6 element. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electronic configuration is [Xe] 4f14 5d2 6s2. In its elemental form hafnium's CAS number is 7440-58-6.The hafnium atom has a radius of 156.4.pm and it's Van der Waals radius is 200.pm. Hafnium is not toxic.
All elemental metals, compounds and solutions may be synthesized in ultra high purity (e.g. 99.999%) for laboratory standards, advanced electronic, thin fillm deposition using sputtering targets and evaporation materials, metallurgy and optical materials and other high technology applications. Information is provided for stable (non-radioactive) isotopes. Organo-Metallic Hafnium compounds are soluble in organic or non-aqueous solvents. See Analytical Services for information on available certified chemical and physical analysis techniques including MS-ICP, X-Ray Diffraction, PSD and Surface Area (BET) analysis.
Hafnium was first discovered by Dirk Coster in 1923.
 hafnium |
 Hafnium |
 afnio |
 Háfnio |
 hafnio |
 Hafnium |
Abundance. The following table shows the abundance of hafnium and each of its naturally occurring isotopes on Earth along with the atomic mass for each isotope.
| Isotope |
Atomic Mass |
% Abundance on Earth |
| Hf-174 |
173.940040 |
0.162 |
| Hf-176 |
175.941402 |
5.206 |
| Hf-177 |
176.943220 |
18.606 |
| Hf-178 |
177.943698 |
27.297 |
| Hf-179 |
178.945815 |
13.629 |
| Hf-180 |
179.946549 |
35.100 |
The following table shows the abundance of Hafnium present in the human body and in the universe scaled to parts per billion (ppb) by weight and by atom:
| |
Typical Human Body |
Universe |
| by Weight |
no data |
0.7 ppb |
| by Atom |
no data |
0.005 ppb |
Safety Data and Biological Role. The safety data for hafnium metal, nanoparticles and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the left margin. Hafnium compounds have no biological role.
Ionization Energy. The ionization energy for hafnium (the least required energy to release a single electron from the atom in it's ground state in the gas phase) is stated in the following table:
| 1st Ionization Energy |
658.52 kJ mol-1 |
| 2nd Ionization Energy |
1437.64 kJ mol-1 |
| 3rd Ionization Energy |
2248.12 kJ mol-1 |
Conductivity. As to hafnium's electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ºC is 33.08 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 1.3. The thermal conductivity of hafnium is 23 W m-1 K-1.
Thermal Properties. The melting point and boiling point for hafnium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
| Heat of Fusion |
25.5 kJ mol-1 |
| Heat of Vaporization |
570.7 kJ mol-1 |
| Heat of Atomization |
618.9 kJ mol-1 |
Recent Research & Development for HafniumFluorescence Signaling of Zr(4+) by Hydrogen Peroxide Assisted Selective Desulfurization of Thioamide.
Hwang J, Choi MG, Eor S, Chang SK.
Inorg Chem. 2012 Jan 19. [Epub ahead of print]
PMID:
22260347
[PubMed - as supplied by publisher]
Hafnium metallocene compounds used as cathode interfacial layers for enhanced electron transfer in organic solar cells.
Park K, Oh S, Jung D, Chae H, Kim H, Boo JH.
Nanoscale Res Lett. 2012 Jan 9;7(1):74. [Epub ahead of print]
PMID:
22230259
[PubMed - as supplied by publisher]
Synthesis of hafnium oxide-gold core-shell nanoparticles.
Dahal N, Chikan V.
Inorg Chem. 2012 Jan 2;51(1):518-22. Epub 2011 Dec 16.
PMID:
22221284
[PubMed - in process]
Di-µ-hydroxido-bis-[tris-(4,4,4-trifluoro-1-phenyl-acetyl-acetonato-?O,O')hafnium(IV)] dimethyl-formamide disolvate.
Viljoen JA, Visser HG, Roodt A.
Acta Crystallogr Sect E Struct Rep Online. 2011 Dec 1;67(Pt 12):m1822-3. Epub 2011 Nov 25.
PMID:
22199601
[PubMed - in process]
Potential of high-Z contrast agents in clinical contrast-enhanced computed tomography.
Nowak T, Hupfer M, Brauweiler R, Eisa F, Kalender WA.
Med Phys. 2011 Dec;38(12):6469.
PMID:
22149830
[PubMed - in process]
Ni ion release, osteoblast-material interactions, and hemocompatibility of hafnium-implanted NiTi alloy.
Zhao T, Li Y, Zhao X, Chen H, Zhang T.
J Biomed Mater Res B Appl Biomater. 2011 Nov 28. doi: 10.1002/jbm.b.31989. [Epub ahead of print]
PMID:
22121018
[PubMed - as supplied by publisher]
Electrochemical oxide nanotube formation on the Ti-35Ta-xHf alloys for dental materials.
Moon BH, Jeong YH, Choe HC.
J Nanosci Nanotechnol. 2011 Aug;11(8):7428-32.
PMID:
22103212
[PubMed - indexed for MEDLINE]
Environmentally stable flexible metal-insulator-metal capacitors using zirconium-silicate and hafnium-silicate thin film composite materials as gate dielectrics.
Meena JS, Chu MC, Wu CS, Ravipati S, Ko FH.
J Nanosci Nanotechnol. 2011 Aug;11(8):6858-67.
PMID:
22103091
[PubMed]
In situ gas phase measurements during metal alkylamide atomic layer deposition.
Maslar JE, Kimes WA, Sperling BA.
J Nanosci Nanotechnol. 2011 Sep;11(9):8226-32.
PMID:
22097559
[PubMed]
Tetra-kis(5,7-dimethyl-quinolin-8-olato-?N,O)hafnium(IV) dimethyl-formamide disolvate.
Viljoen JA, Visser HG, Roodt A.
Acta Crystallogr Sect E Struct Rep Online. 2011 Oct 1;67(Pt 10):m1428-9. Epub 2011 Sep 30.
PMID:
22058710
[PubMed]
Synthesis, characterization, and materials chemistry of Group 4 silylimides.
Cosham SD, Johnson AL, Molloy KC, Kingsley AJ.
Inorg Chem. 2011 Dec 5;50(23):12053-63. Epub 2011 Nov 4.
PMID:
22053704
[PubMed - in process]
Preparation and physical properties of early-late heterobimetallic compounds featuring Ir-M bonds (M = Ti, Zr, Hf).
Curley JJ, Bergman RG, Tilley TD.
Dalton Trans. 2012 Jan 7;41(1):192-200. Epub 2011 Oct 21.
PMID:
22020701
[PubMed - in process]
New stable aryl-substituted acyclic imino-N-heterocyclic carbene: synthesis, characterisation and coordination to early transition metals.
Larocque TG, Badaj AC, Dastgir S, Lavoie GG.
Dalton Trans. 2011 Dec 21;40(47):12705-12. Epub 2011 Oct 18.
PMID:
22006062
[PubMed - in process]
Sterically demanding hetero-substituted [2]borametallocenophanes of group IV metals: synthesis, structure and reactivity.
Braunschweig H, Dörfler R, Mies J, Oechsner A.
Chemistry. 2011 Oct 17;17(43):12101-7. doi: 10.1002/chem.201101774. Epub 2011 Sep 9.
PMID:
21905138
[PubMed]
The role of electron localization in the atomic structure of transition-metal 13-atom clusters: the example of Co13, Rh13, and Hf13.
Piotrowski MJ, Piquini P, Cândido L, Da Silva JL.
Phys Chem Chem Phys. 2011 Oct 14;13(38):17242-8. Epub 2011 Aug 30.
PMID:
21879054
[PubMed - indexed for MEDLINE]
Monte Carlo dose enhancement studies in microbeam radiation therapy.
Martínez-Rovira I, Prezadoa Y.
Med Phys. 2011 Jul;38(7):4430-9.
PMID:
21859044
[PubMed - indexed for MEDLINE]
Electronic structure characterization of La incorporated Hf-based high-k gate dielectrics by NEXAFS.
Yamamoto T, Ogawa S, Kunisu M, Tsuji J, Kita K, Saeki M, Oku Y, Arimura H, Kitano N, Hosoi T, Shimura T, Watanabe H.
J Nanosci Nanotechnol. 2011 Apr;11(4):2823-8.
PMID:
21776638
[PubMed - indexed for MEDLINE]
Oxygen-containing gas-phase diatomic trications and tetracations: ReO(z+), NbO(z+) and HfO(z+) (z=3, 4).
Brites V, Franzreb K, Harvey JN, Sayres SG, Ross MW, Blumling DE, Castleman AW Jr, Hochlaf M.
Phys Chem Chem Phys. 2011 Sep 7;13(33):15233-43. Epub 2011 Jul 15.
PMID:
21761073
[PubMed]
Tris(?-cyclo-penta-dien-yl)hafnium(III).
Burlakov VV, Arndt P, Spannenberg A, Rosenthal U.
Acta Crystallogr Sect E Struct Rep Online. 2011 May 1;67(Pt 5):m629. Epub 2011 Apr 22.
PMID:
21754338
[PubMed]
Synthesis of freestanding HfO2 nanostructures.
Kidd T, O'Shea A, Boyle K, Wallace J, Strauss L.
Nanoscale Res Lett. 2011 Apr 5;6(1):294.
PMID:
21711786
[PubMed - in process] |
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