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
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 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.All elemental metals, compounds and solutions may be synthesized in ultra high purity (e.g. 99.999%) for laboratory standards, advanced electronic, metallurgy and optical materials and other high technology advantages. 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.
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. |
hafnium
Hafnium
afnio
Háfnio
hafnio
HafniumIsotope |
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 |
Safety Data. 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.
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 |
| Formula | Atomic Number | Molecular Weight | Electronegativity (Pauling) | Density | Melting Point | Boiling Point |
Vanderwaals radius |
Ionic radius | Energy of first ionization |
| Hf | 72 | 178.49 g.mol -1 | 1.3 | 13.07 g.cm-3 at 20 °C | 2200 °C | 5200 °C | 200.pm | 0.075 nm (+4) | 658.52 kJ.mol-1 |
| PRODUCT CATALOG | U.S. Operations | Submicron & Nanopowder | Tolling | Ultra High Purity | Sputtering Target | Crystal Growth | Rod, Plate, Powder, etc. | Foil |
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