| Hafnium | |
| Electrons per shell | 2,8,18,32,10,2 |
| Electron Configuration | [Xe] 4f14 5d2 6s2 ![]() |
| Ground state | 3F2 |
| Atomic Volume | 13.6 cm3 mol-1 |
| Electronegativity | 1.3 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 5.3 x 10-9 |
| Molar magnetic susceptibility | 9.46 x 10-10 |
| Speed of sound | 3010 m s-1 |
Thermal Properties |
|
| Enthalpy of Atomization | 703 kJ mol-1 @25°C |
| Enthalpy of Fusion | 25.5 kJ mol-1 |
| Enthalpy of Vaporisation | 570.7 kJ mol-1 |
| Heat Capacity | 25.73 J mol-1 K-1 |
| Thermal Conductivity | 23.0 W m-1 K-1 |
| Thermal Expansion | 5.9 μm m-1 K-1 |
| Critcal Temperature | No data. |
| Critcal Pressure | No data. |
| Adiabatic index | No data. |
Hardness |
|
| Brinell hardness | 1700 MPa |
| Mohs hardness | 5.5 |
| Vickers hardness | 1760 MPa |
Elastic Properties |
|
| Bulk modulus | 110 GPa |
| Poisson ratio | 0.37 |
| Shear modulus | 30 GPa |
| Young's modulus | 78 GPa |
Electrical Properties |
|
| Electrical resistivity | 3.0 x 10-7 Ω m |
| Electrical conductivity | 0.0312 106/cm Ω |
Chemical Properties |
|
| Electrochemical Equivalent | 1.6649 g Ah-1 |
| Electron Work Function | 3.9 eV |
| Valence Electron Potential (-eV) | 81 |
| Ionization Potential | |
| 6.65 | |
| 14.925 | |
| 23.32 | |
| Incompatibilities | Strong oxidizers, chlorine. |
Flammability |
|
Energy Levels |
|
| 55.7902 KeV | |
| 54.6114 KeV | |
| 63.234 KeV | |
| 64.3746 KeV | |
| 63.109 KeV | |
| 7.899 KeV | |
| 7.8446 KeV | |
| 9.0227 KeV | |
| 9.3473 KeV | |
| 9.1599 KeV | |
| 8.9039 KeV | |
| 10.5158 KeV | |
| 10.8324 KeV | |
| 8.137 KeV | |
| 6.9583 KeV | |
Atomic Radii |
|
| 155 pm | |
| 208 pm | |
| 150 pm | |
| No data. | |
| 122 pm | |
| 159 pm | |
Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 4 | IV | 0.72 | 0.58 | R |
| VI | 0.85 | 0.71 | R | |
| VII | 0.9 | 0.76 | ||
| VIII | 0.97 | 0.83 | ||
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
Oxidation States |
|
| Hf+4 | |
| Hf+1, Hf+2, Hf+3 | |
Ionisation Energies (kJ mol-1) ![]() |
|
| 642 | |
| 1440 | |
| 2250 | |
| 3216 | |
Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 2689 | 2954 | 3277 | 3679 | 4194 | 4876 |
Crystal Structure |
|
| Hexagonal close packed | |
![]() |
a = 319.64 pm |
| b = 319.64 pm | |
| c = 505.11 pm | |
| α = 90° | |
| β = 90° | |
| γ = 120° | |