Samarium Element

Of these, 4 isotopes are stable, Sm, 150Sm, Sm, and Sm, and three are radioactive isotopes, which, however, are extremely long-lived ( Sm, Sm and with half-lifes 1.0 x lO years) (Table 3.7). 

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As a research tool, X-rays also advanced the study of the elements. Moseley s work from 1913 on X-ray spectra had shown that the order of the elements in the periodic table was the result not simply of chance but of some fundamental principle of atomic structure. It confirmed the ordering of some problematic elements and revealed that there was a missing element in the rare-earth series between neodymium and samarium. Element 61, promethium, was officially added to the periodic table in 1949. 

Analoge Verhaltnisse liegen bei Element 61 vor. Hier kommen be-kanntlich bei Neodym und Samarium die fiir das Element 61 in Frage... 

The compounds of the rare earth elements are usually highly colored. Neodymium s compounds are mainly lavender and violet, samarium s yellow and brown, holmium s yellow and orange, and erbium s rose-pink. Europium makes pink salts which evaporate easily. Dysprosium makes greenish yellow compounds, and ytterbium, yellow-gold. Compounds of lutetium are colorless, and compounds of terbium are colorless, dark brown, or black. 

Different lanthanide metals also produce different emission spectrums and different intensities of luminescence at their emission maximums. Therefore, the relative sensitivity of time-resolved fluorescence also is dependent on the particular lanthanide element complexed in the chelate. The most popular metals along with the order of brightness for lanthanide chelate fluorescence are europium(III) > terbium(III) > samarium(III) > dysprosium(III). For instance, Huhtinen et al. (2005) found that lanthanide chelate nanoparticles used in the detection of human prostate antigen produced relative signals for detection using europium, terbium, samarium, and dysprosium of approximately 1.0 0.67 0.16 0.01, respectively. The emission... 

These include the following 14 elements cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmi-um, erbium, thulium, ytterbium, and lutetium. 

We were quite elated, and it appeared that it was a rich field. Now, fifty years later, I must say that it wasn t as rich as we thought. But we have over the years discovered half a dozen natural radioactive elements, and two of these, the samarium-147 with its decay to neodymium-143 and rhenium-187 with its decay to osmium-187, prove to be of use in Nuclear Dating. The importance of rhenium is that it is iron soluble while the other radioactivities are insoluble in metallic iron. In fact, the best half life we have for rhenium-187 was obtained by measuring the osmium-187 to rhenium-187 ratio in iron meteorites which had been dated by other methods. This work was started many years ago by Dr. Herr and others in Germany. The half life is 43,000,000,000 years. 

A kind of summary of the similarities which, albeit with some uncertainties, may be evidenced between the single lanthanide and actinide metals is reported, according to Ferro et al. (2001a) in Fig. 5.13. According to this scheme the alloying behaviour of plutonium could be simulated by cerium whereas a set of similarities may especially be considered between the block of elements from praseodymium to samarium with those from americium to californium. 

Samarium - the atomic number is 62 and the chemical symbol is Sm. The name derives from the mineral Samarskite, in which it was found and which had been named for Colonel von Samarski , a Russian mine official. It was originally discovered in 1878 by the Swiss chemist Marc Delafontaine, who called it decipium. It was also discovered by the French chemist Paul-Emile Lecoq de Boisbaudran in 1879. In 1881, Delafontaine determined that his decipium could be resolved into two elements, one of which was identical to Boisbaudran s samarium. In 1901, the French chemist Eugene-Anatole Demar9ay showed that this samarium earth also contained europium. 

Samarium is one of the few elements with several stable isotopes that occur naturally on Earth. 

Samarium is the 39th most abundant element in the Earths crust and the fifth in abundance (6.5 ppm) of all the rare-earths. In 1879 samarium was first identified in the mineral samarskite [(Y, Ce U, Fe) (Nb, Ta, Ti )Ojg]. Today, it is mostly produced by the ion-exchange process from monazite sand. Monazite sand contains almost all the rare-earths, 2.8% of which is samarium. It is also found in the minerals gadolmite, cerite, and samarskite in South Africa, South America, Australia, and the southeastern United States. It can be recovered as a byproduct of the fission process in nuclear reactors. 

Using a spectrometer in 1853, Jean Charles-GaUisard de Marignac (1817—1894) suspected that dydimia was a mixture of yet-to-be-discovered elements. However, it was not until 1879 that Paul-Emile Locoq de Boisbaudran (1838—1912), using a difficult chemical fractionation process, discovered samarium in a sample of samarskite, calling it samarium after the mineral, which was named for a Russian mine official. Colonel von Samarski. Samarskite ore is found where didymia is found. Didymia ( twins ) was the original name given to a combination of the two rare-earths (praseodymium and neodymium) before they were separated and identified. 

In 1896 Eugene-Anatole Demarcay (1852-1904), a French chemist, was working with a sample of samarium when he realized that it was contaminated by an unknown element. He was able to separate the two (samarium and europium) in 1901 by a long and tedious process. He is given credit for the discovery of europium and was the one to give the new element its... 

Other chemists also worked to separate gadolinium from the mineral dydimia. Paul-Emile Locoq de Boisbaudran, following clues provided by Marignac, isolated element 62 (samarium)... 

Harrison W. J. (1977). An experimental study of the partitioning of samarium between garnet and liquid at high pressures. In Papers Presented to the International Conference on Experimental Trace Elements Geochemistry, Sedona, Arizona. 

Boisbaudran obtained this rare earth element in 1892 in basic fractions from samarium-gadolinium concentrates, but it was not identified for several years. Demarcay obtained the element in the pure form in 1901. The element was named after Europe. It is found in nature mixed with other rare earth elements. Its concentration, however, is much lower than most other lanthanide elements. The principal rare earth ores are xenotime, monazite, and bastna-site. 

Mosander extracted from the mineral lanthana a rare earth fraction, named didymia in 1841. In 1879, Boisbaudran separated a rare earth oxide called samaria (samarium oxide) from the didymia fraction obtained from the mineral samarskite. Soon after that in 1885, Baron Auer von Welsbach isolated two other rare earths from didymia. He named them as praseodymia (green twin) and neodymia (new twin) after their source didymia (twin). The name praseodymium finally was assigned to this new element, derived from the two Greek words, prasios meaning green and didymos meaning twin. 

The discovery of samarium is credited to Boisbaudran, who in 1879 separated its oxide, samaria from Mosander s didymia, the mixture of rare earth oxides from which cerium and lanthanum were isolated earher. Demarcay in 1901 first identified samaria to be a mixture of samarium and europium oxides. The element got its name from its mineral, samarskite. The mineral, in turn, was named in honor of the Russian mine official Col. Samarki. 

Samarium ore usually is digested with concentrated sulfuric or hydrochloric acid. The extraction process is similar to other lanthanide elements. Recovery of the metal generally consists of three basic steps. These are (1) opening the ore, (2) separation of rare earths first to various fractions and finally to their individual compounds, usually oxides or halides, and (3) reduc-... 

Important is the use of light rare earth elonents for production of hard magnetic materials. Most prominent are alloys of samarium with cobalt in the atomic ratio 1 5 or 2 17. It may also be assumed that in further development of these materials on a larger scale that praseodymium, neodymium, lanthanum and also individual heavy rare ecu h elements will be used to achieve particular effects. Interesting is the development of magnetic bubble memories based on gadolinium-galliiimrgarnets. 

Seccand example - In the production of samariumcobalt permanent magnets impurities have practically only a dilution effect. One can therefore use instead of a 99.9 % pure samarium metal a significantly cheaper 90 %, perhaps even 80 % pure metal vdth the balance other rare earths. In any case, it is necessary in this instance that the conposition of the other rare earth elements be held constant, vdiich is not always quite so siitple. 

By increasing the temperature of an ion exchange system, more rapid separation can be performed. In fact, temperature modifies the separation factor of two neighbor elements. For example, by increasing the temperature from 25°C to 95°C, the 1.5 samarium-europium separation factor becomes 1.8 and the europium-gadolinium 1.1 separation factor goes to 1.5. Thus the difficult Eu-Gd separation at 25°C becomes "easy" at 95°C. 

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