Molecular Formula | Sm |
Molar Mass | 150.36 |
Density | 7.47 g/mL at 25 °C (lit.) |
Melting Point | 1074 °C (lit.) |
Boling Point | 1794 °C (lit.) |
Water Solubility | Insoluble in water. |
Appearance | powder |
Specific Gravity | 7.4 |
Color | Silvery-gray |
Exposure Limit | ACGIH: TWA 2 ppm; STEL 4 ppmOSHA: TWA 2 ppm(5 mg/m3)NIOSH: IDLH 25 ppm; TWA 2 ppm(5 mg/m3); STEL 4 ppm(10 mg/m3) |
Merck | 13,8425 |
Storage Condition | Store below +30°C. |
Sensitive | Air & Moisture Sensitive |
MDL | MFCD00011233 |
Use | Used as samarium-cobalt permanent magnet material |
Risk Codes | R11 - Highly Flammable R15 - Contact with water liberates extremely flammable gases R33 - Danger of cumulative effects |
Safety Description | S16 - Keep away from sources of ignition. S30 - Never add water to this product. S33 - Take precautionary measures against static discharges. |
UN IDs | UN 3089 4.1/PG 3 |
WGK Germany | 3 |
FLUKA BRAND F CODES | 1-10 |
TSCA | Yes |
HS Code | 28053019 |
Hazard Class | 4.2 |
Packing Group | I |
Downstream Products | Gadolinium Oxide Samarium (III) oxide Europium Oxide |
resistivity | 91.4 ++-cm, 0°C |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Introduction | samarium symbol Sm, atomic number 62, is a soft silver metal element of the lanthanide series. It is found in monazite and basalt. There are 7 kinds of stable isotopes of samarium, in addition to Sm147 (very weak radioactivity (half-life of 2.5 × 1011 years), the rest are all stable. This metal is a neutron absorber and can be used in the manufacture of special alloys of nuclear reactor components. Samarium has a certain degree of oxidation resistance in the air, but with the passage of time will form a yellow oxide. Ignition was carried out at a lower temperature of 150°C. It is an excellent reducing agent that releases hydrogen when immersed in water and has the ability to absorb neutrons in a nuclear reactor. |
History of discovery | samarium was discovered in 1879 by the French chemist, Paul, and named after the mineral yttrium niobium ore (Samarskite) isolated therefrom. The mineral itself was previously named after a Russian mining officer, Col. Vassili-Samarski-buekhovitz (Samarsky-Bykhovets), he thus indirectly became the first person whose name was used to be named a chemical element. Although samarium is classified as a rare earth element, it is the 40th highest content element in the Earth's crust and is more common than metals such as tin. Samarium exists in several minerals, including cerium ore, Silicon beryllium yttrium ore, niobium yttrium ore, monazite and fluorocarbon cerium ore, the concentration of up to 2.8%, the latter two are the most common commercial sources. These minerals are mainly distributed in China, the United States, Brazil, India, Sri Lanka and Australia; China is by far the world's leader in the mining and production of samarium. |
Source | samarium is the 39th most abundant element in the crust, and in all rare earth elements (content of 6.5 ppm) ranked fifth. In 1879, samarium was first discovered and confirmed in the mineral Stone [[Y,Ce U,Fe)3(Nb,Ta,Ti5)O16]. Today, it is mainly produced from monazite sand by ion exchange processes. Monazite sand contains almost all rare earths, of which 2.8% are samarium. It is also found in gabbros, cerite and zinc ores in South Africa, South America, Australia and the southeastern United States. It can also be recovered as a by-product of the nuclear reactor fission process. |
Application | samarium is light yellow, which is the raw material of samarium-cobalt permanent magnet, strontium cobalt magnets are the first rare earth magnets to be used in industry. There are two types of such permanent magnets: SmCo5 system and Sm2Co17 system. In the early 70 s, the SmCo5 system was invented, and the Sm2Co17 system was invented. Now is the main needs of the latter. The purity of the samarium oxide used in the Samarium Cobalt Magnet does not need to be too high. From the viewpoint of cost, about 95% of the products are mainly used. In addition, samarium oxide is also used in ceramic capacitors and catalysts. In addition, samarium also has nuclear properties, which can be used as structural materials, screen materials and control materials for atomic energy reactors, so that the huge energy generated by nuclear fission can be used safely. |
uses | The radioisotope samarium -153 is the active ingredient of the drug samarium (153Sm), which is used to treat lung cancer, prostate cancer, the active ingredient of the drug "Quadramet" for breast cancer and osteosarcoma, kills cancer cells. Another isotope, samarium -149, is a strong neutron absorber and is therefore added to the control rods of a nuclear reactor. It will also form decay products during the operation of the reactor, which is one of the important factors considered in the design and operation of the reactor. Other applications of samarium include catalysts for chemical reactions, radiometric dating, and X-ray lasers. used as samarium-cobalt permanent magnet material |
preparation | reduction distillation of samarium oxide: the advantage of the reduction-distillation method is the direct use of rare earth oxides as raw materials, the reduction and distillation processes are performed simultaneously, thereby simplifying the process. The purity of the obtained metal product is high. In addition, the residue produced by the reduction distillation is also a rare earth oxide, and can be recycled. Because samarium has a high vapor pressure, the reducing agent lanthanum has a low vapor pressure. La:1754 ℃, the vapor pressure is 1.33, 2217 ℃, the vapor pressure is 133.32PaSm:722 ℃, the vapor pressure is 1.33, 964 ℃, the vapor pressure is 133.32Pa, so the metal samarium can be prepared by lanthanum reduction distillation of oxide: 2La(l) Sm2O3(s)1600 La2O3(s) 2Sm(g) the Sm produced in the reaction can be removed from the reactor by volatilization, thus facilitating the reaction to be complete. |
harmfulness | samarium salts are toxic if ingested. These salts react with water to release potentially explosive hydrogen. |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |