Auer metal

You may find lanthanides as the flint in cigarette lighters for example, alloys of cerium and iron form a material called auer metal. When it s struck, it... 

Auer-brenner) m. Welsbach burner, -licht) n. Welsbach light, -metall) n. Welsbach metal (pyrophoric cerium alloy), auf) prep, on, upon, in, at about into, to. 

Lutetium (Lu, [Xe]4/ 145 / 6.v2), name and symbol after the Latin word Lutetia (Paris). Discovered (1907) by Georges Urbain and Carl Auer von Welsbach. Silvery white metal. 

Eng HW, Barnes PW, Auer BM, Woodword PM (2003) Investigation of the electronic structure of d° transition metal oxides belonging to the perovskite family. J Solid State Chem 175 94-109... 

In ignition, electric incandescent lartps were far superior to the Auer lights. But this situation was ameliorated in 1903 vhen von Welsbach was granted a patent for a pyrophoric metal alloy ("flintstone") ccnposed of 70 % mischmetal and 30 % iron, Ihis patent was also streniKxisly litigated but victoriously defended. 

Early in his life he left his children such a large inheritance that his son Karl was able to pursue his studies of chemistry in 1878 in Vienna with Professor lAjeSaen and in 1880 with Bunsen in Heidelberg without material worries. In the laboratory of Bunsen he was first introduced into the chemistry of the rare earth elements. Uhtil his death in 1929 he remained true to this field of work. The intensive involvement in spectroscopy with Bunsen also made him familiar with the problems of radiant li t v ch without doiibt was important for his later invention of Auer-Li t and with that the use of the rare earth elements. Further, he had an insight into the work of winning the rare earth metals from their salts through Bunsen, Hill rand and Norton A)o succeeded for the first time in 1875 to produce rare ecu h metals by electrolysis vhich later was further developed in Munich by Muthmann. Ihe concepts "pyrophor" and "pyrophoricity" originate from Auer von Welsbach. 

Up to now, the sdB/sdOB stars, the classical sdOs and the extremely helium-rich luminous sdOs have been analyzed for the most important (and accessible) metal abundances. The analyses usually require extensive non-LTE line formation calculations to solve the statistical equilibrium in detailed model atoms simultaneously with the radiative transfer equations for all relevant frequencies. With the advent of computer codes based on modern powerful solution algorithms (Auer and Heasley, 1976 Werner and Husfeld, 1985) it has now become possible to test (and eventually remove) approximations necessary in older computations. This and the availability of improved atomic data make the non-LTE predictions more reliable, and obstacles in obtaining accurate abundance determinations come now mainly from the observational side where high-quality spectra are needed to identify and to measure weak... 

E. Auer, A. Freund, J. Pietsch and T. Tacke. Carbons as supports for industrial precious metal catalysts. Applied Catalysis A General, 173, 259-271 (1998). 

The ignition point of metallic cerium is 160 C, which is quite low. However simple cerium is too soft to use and it is easily oxidized in the air. Therefore it is mixed with iron to form an alloy. This alloy of cerium and iron in v/eight ratio 65 35 is called Auer s metal. Nickel and cobalt-etc. can also be used instead of iron. Other kinds of alloys consisting of aluminium, magnesium and silicon are also used. 

Properties Cryst. solid, metallic luster sol. in dil. acids reacts slowly with water at.wt. 164.9303 dens. 8.803 vapor pressure 2 mm (1630 C) m.p. 1470 C b.p. 2720 C magnetic and elec, props. Precaution Can react violently with air or halogens oxidizes rapidly in moist air Uses Getter in vacuum tubes, research in electrochemistry, spectroscopy Manuf./Distrib. Aldrich http //www.sigma-aldrich.com] Atomergic Chemetals http //www.atomergic.com] Auer-Remy Cerac http //www.cerac.com] Fluka http //www.sigma-aldrich.com... 

Discovery Three scientists, G. Urbain in France, C. Auer von Welsbach in Austria and C. James in the USA investigated ytterbium carefully. In 1907, independently of each other, th discovered a new metal. Urbain called the new element lutecium after an old name for Paris. Auer wanted to use the name cassiopeium. In 1909 it was decided that the name should be lutetium. 

Auer von Weis bach in Austria developed a new separation method. If a mixture of RE oxides is attacked by nitric acid the most basic oxides dissolve, while the less basic will be enriched in the insoluble residue. By using this method he was able, in 1884, to separate lanthanum (the more basic) from didymium. He continued to apply the same method to the didymium fraction and carried out more than 100 fractional crystallizations, each taking two days. In this way didymium was separated into two main fractions. In 1885, spectroscopic studies confirmed that two different elements were present. Auer called the green-colored one praseodymium, the green twin", while the other got the name neodymium, the new twin". This naming has been accepted, although it involved a deviation from the earlier rule that when a supposedly pure RE metal is divided in two, one of the elements shall keep the older name, while the other is given a new name by the discoverer. 

Auer was bom in Vienna in 1858 and died in 1929. He studied chemistry in the University of Vienna and continued in Heidelberg for two or three years in the early 1880s. While studying inorganic chemistry, he became especially interested in the rare earth metals and was encouraged by Robert Bunsen to choose this field of activity. Even if his time in Heidelberg was short, Auer kept close contact right up to Bunsen s death in 1899. 

Auer needed other and cheaper sources of raw material and found them in monazite sand, containing thorium and rare earth elements, from the United States and Brazil. Auer isolated thorium and made mantles of its oxide. He formd, however, that impure thorium oxide was better than pure. By energetic and systematic work he formd that the optimal condition was thorium oxide mixed with 1% cerirrm oxide. And now he could go out to capture the market The new dazzling Ught was introduced in the fall darkness outside the Opem Cafe in Vienna on 4 November 1891. The new oxide mixture became a worldwide success. Almost 100000 Auer mantles were sold within nine months. The aura of mysticism that had been associated with the rare earth elements increased rather than disappeared, although Auer had found and demonstrated the first industrial application for the metals. Many cities... 

About Auer von Welsbach it must be said that he - as a scientist, inventor and industrialist - improved the living conditions for people of his time. By his achievement with the metal filament lamp he also exerted a great influence on the welfare of following generations. 

With rare earth metals he was more successful. He was originally inspired to research in this field by Lecoq de Boisbaudran, among others. Even ifhe had to sustain bitter fights with Auer, they ended with a recognized priority for the discovery of the element lutetium. 

Many discoverers of rare earth metals from 1880 and later were dead when the nomination process began. Some, however, were still active (the year of death is given in parentheses) Demargay (1904), Cleve (1905), Delafontaine (1911), Boisbaudran (1912), James (1928), Auer (1929), and Urbain (1938). Auer and Urbain were seriously discussed for the prize. Auer was nominated 10 times between 1908 and 1929, Urbain 56 times between 1912 and 1936. None of them, however, was awarded the prestigious prize [17.10]. 

Different, more specific, separation techniques were developed, each one having its special characteristics. It could be separation of other double salts - nitrates, oxalates - composed of a RE metal ion and another cation present in the solution, for example K+, Na+, NH or Mg. Double ammonium nitrate may be used for removal of lanthanum and the separation of neodymium from praseodymium. Members within the cerium group may be separated using double manganese nitrates, while elements in the yttrium group are separated using the differences in solubihty of their bromates. Auer von Welsbach did much work with RE-ammonium oxalate systems. Charles James in the USA developed an effective technique with RE-magne-sium double salts. 

That the rare earth metals are of little practical value was the general view during the whole of the 19 century. The turn of the century, however, saw the first major application, Auer von Welsbach s incandescent mantle for gas lightning (section 17.4.10.2). Gradually the list of RE applications was increased. At first the RE metals were used mixed, just as they were prepared from monazite sand. One example is mischmetall, consisting of about 50% cerium, 25% lanthanum and 25% other rare... 

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