Samarium metal.

In the air, samarium slowly oxidizes, covering first with a dark film of Sm2O3 oxide, and then crumbles into a powder with a yellow tint.

Samaria - a highly active metal. It is soluble in acids, burns in air (forming oxide), reacts with nitrogen (forming nitride), carbon (forming carbides), chalcogenides (forming mono and two-trivalent sulphides, selenides, tellurides), hydrogen (forming hydrides), silicon (forming silicides), boron (forming borides), phosphorus (phosphides), arsenide (arsenides), antimony (antimonides), chlorodides, chloride (all chloride) and all chlorides.

Chemical properties

Application

Magnetic materials

Samaria is widely used for the production of heavy-duty permanent magnets, in an alloy of samarium with cobalt and a number of other elements. And although in this area in recent years, there has been a displacement of samarium-cobalt magnets by neodymium-based magnets, nevertheless, the possibilities of samarium alloys are far from exhausted.

When doping its alloys with cobalt with elements such as zirconium, hafnium, copper, iron and ruthenium, a very high value of coercive force and residual induction was achieved. In addition, ultrafine powders of its high-performance alloys, obtained by spraying in the atmosphere of helium in an electric discharge, with subsequent pressing and sintering, make it possible to obtain permanent magnets with more than 3 times better magnetic energy and field characteristics than other magnetic alloys based on rare earth metals.

Thermoelectric materials

The newly discovered thermoEMF generation effect in samarium monosulphide SmS has a very high efficiency of about 50%. Already when heating the SmS single crystal to 130 ° C (which opens the prospect for the utilization of low-potential heat), when such an effect is jointly operated with thermoelectronic emission or classical thermoelectric elements, it is easy to achieve an efficiency of electricity generation at the level of 67-85%, which is very important due to the decreasing reserves of organic fuel on the planet. Even today, experienced generators are competitive compared to any thermal engine (including the engine of Diesel and Stirling), which allows you to think about the introduction of this effect as the main power plant on the car. Given the ultra-high radiation resistance of samarium, samarium monosulphide can be used to design nuclear reactors that directly convert heat and partially ionizing radiation into electricity (space reactors, reactors for deep space). Thus, monosulphide samarium can take a leading role in the near future in small and large energy, the production of space-based nuclear power plants and air transport, in the production of power plants for cars of the future, compact and powerful sources of current for domestic needs and in military affairs. It is interesting to note that on the basis of the use of samarium monosulphide it is quite easy to solve the problem of creating a nuclear power plant for road transport, and at the same time quite safe (nuclear car).

Samaria telluride is also used as a thermoelectric material (thermoEMS 320 μV / K).