Samarium is a chemical element with the symbol Sm and atomic number 62.
Samarium is a rare earth metal, with a bright silver luster, that is reasonably stable in air; it ignites in air at 150 °C. Even with long-term storage under mineral oil, samarium is gradually oxidized, with a grayish-yellow powder of the oxide-hydroxide being formed. Three crystal modifications of the metal also exist, with transformations at 734 and 922 °C.
| Technical Data | ||||||||
| Symbol | Sm | Density (25 C)/gcm | 7.536 | |||||
| Atomic number | 62 | Melting point /°C | 1072 | |||||
| No. of naturally occurring isotopes | 7 | Boiling point /°C | 1800 | |||||
| Atomic weight | 150.36 (+/-3) | ΔHfus/kJmol-1 | 8.9(+/-0.4) | |||||
| Outer electron configuration | 4f6s2 | ΔHvap/kJmol-1 | 165(+/-17) | |||||
| Metal radius(6-coordinate)/pm | 180.4 | ΔHf(monoatomic gas)/kJmol-1 | 207 | |||||
| Ionic radius(6-coordinate)/pm III | 95.8 | ΔH(hydration Ln3+)/kJmol-1 | 3515 | |||||
| Ionic radius(7-coordinate)/pm II | 122 | Ionization energy/kJmol-1 I | 542 | |||||
| E° (M3+(aq)\ + e- →M2+(aq))/V | -1 | Ionization energy /kJmol-1 II | 1068 | |||||
| E° (M3+(aq)\ + 3e- →M(s))/V | -2.414 | Ionization energy/kJmol-1 III | 2285 | |||||
| Electrical resistivity (25 °C)/μohm cm | 92 | |||||||
| Evaporation Techniques | ||||||||
| Temperature (oC) @Vap. Pressure | Techniques | Remarks | ||||||
| 10-8 Torr | 10-6 Torr | 10-4 Torr | Electron Beam | Crucible | Coil | Boat | ||
| 373 | 460 | 573 | Good | Al2O3 | - | Tantalum | Go to Evaporation Sources Page | |