Карл Ауэр фон Вельсбах: Химик и изобретатель редких земель

Austrian scientist and inventor (1858–1929)
infobox scientist
| name = Carl Auer von Welsbach
| image = Auer von Welsbach. jpg
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| birth name = Carl Auer
| birth date =
| birth place = Vienna, Austrian Empire
| death date = Died: 1929 08 04 (aged 70)
| death place = Welsbach Castle, Mölbling, Austria
| other names = Carl Freiherr Auer von Welsbach
| field = Chemistry
| work institutions =
| alma mater = University of ViennaUniversity of Heidelberg
| doctoral advisor = Robert Bunsen
| doctoral students =
| known for = rare earth elementsdiscovery of praseodymiumdiscovery of neodymiumdiscovery of lutetiumlighting improvements
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| author abbrev zoo =
| influences =
| influenced =
| prizes = Elliott Cresson Medal (1900)Wilhelm Exner Medal (1921)
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| spouse = ubl|
Marie Anna Nimpfer who received the Austrian noble title of Freiherr Auer von Welsbach in 1901, was an Austrian scientist and inventor, who separated didymium into the elements neodymium and praseodymium in 1885. He was also one of three scientists to independently discover the element lutetium (which he named cassiopeium), separating it from ytterbium in 1907, setting off the longest priority dispute in the history of chemistry. He took the phrase plus lucis, meaning "more light", as his motto. He was the youngest of four children, his elder siblings being Leopoldine, Alois and Amalie. His father, ennobled in 1860 (as Alois Ritter Auer von Welsbach), was director of the Imperial printing office (K. k. Hof und Staatsdruckerei) in the days of the Austrian Empire. Next, he joined the Austro Hungarian Army for one year of voluntary military service. He was commissioned as a Second Lieutenant. He joined on October 1, 1877, and received his patent as a lieutenant on December 15, 1878. The name "neodidymium" is derived from the Greek words neos (νέος), new, and didymos (διδύμος), twin. The name praseodymium comes from the Greek prasinos (πράσινος), meaning "green". In naming both elements, and not leaving the original name didymium to the more abundant component, Auer von Welsbach diverged from established practice, which was to give a new name only to the less abundant component. Nonetheless, his name for the major fraction, neodidymium, after some modification, became the name of the element neodymium. Praseodymium was also accepted as the name of the minor fraction.

The rare earth element lutetium was independently discovered by three scientists at around the same time in 1907: French scientist Georges Urbain, Austrian Auer von Welsbach, and American Charles James. All three were successful in separating the substance then known as ytterbium into two new fractions. To name the newly discovered fraction,
Urbain suggested the name "lutecium", for the Roman city of Lutetia that preceded Paris. Auer von Welsbach suggested the name "cassiopeium". James' work was not yet published when the other's work appeared, and he did not involve himself in subsequent disputes. Lutetium, a slight modification of Urbain's name, was eventually accepted after a long battle between Urbain and Welsbach. A lawsuit (Wagner v. Coleman) was brought against Coleman. The company changed its formulation to use non radioactive materials, which apparently cost less and last longer.

Auer von Welsbach then started work on development of metal filament mantles, first with platinum wiring, and then osmium. Osmium is very difficult to work with, but he developed a new method, which mixed osmium oxide powder with rubber or sugar into a paste, which is then squeezed through a nozzle and fired. The paste burns away, leaving a fine wire of osmium. Welsbach's flints consisted of pyrophoric alloys, 70% cerium and 30% iron, which when scratched or struck would give off sparks. This system remains in wide use in cigarette lighters today. In 1907 he formed Treibacher Chemische Werke GesmbH to build and market the devices. Between 1907 and 1918, Auer von Welsbach focused on isolating preparations of actinium and thorium as by products of radium extraction. He presented a major paper on his spectroscopic work and the separation of radioactive elements in 1922. The following photographs show scientific equipment from Auer von Welsbach's laboratory, from "Spektroskopische Methoden der analytischen Chemie" (1922).]] In 2008 (150 years after his birth), Auer von Welsbach was selected as a main motif for a high value collectors' coin: the Austrian €25 Fascination Light. He was also depicted on postage stamps of 1936, 1954 and 2012.