Terbium discovery

It should be noted that the ytterbium listed above was a mixture discovered in the mineral erbia by de Marignac in 1878 and not the neoytterbium/aldebaranium element renamed ytterbium that was foimd in the mineral ytterbia. The columbium was a mixture found in the mineral samarskite and was not the present day columbium/niobium. The ionium listed above was a mixture of terbium and gadolinium that was found in the mineral yttria and does not refer to °Th. Finally, the neptunium refers to material fovmd in niobium/tantalum minerals and does not refer to the 1940 discovery of the trans-uranium element produced via a neutron capture reaction on a uranium sample. 

Dysprosium - the atomic number is 66 and the chemical symbol is Dy. The name derives from the Greek dysprositos for hard to get at , due to the difficulty in separating this rare earth element from a holmium mineral in which it was found. Discovery was first claimed by the Swiss chemist Marc Delafontaine in the mineral samarskite in 1878 and he called it philippia. Philippia was subsequently found to be a mixture of terbium and erbium. Dysprosium was later discovered in a holmium sample by the French chemist Paul-Emile Lecoq de Boisbaudron in 1886, who was then credited with the discovery. It was first isolated by the French chemist George Urbain in 1906. 

In the 1800s chemists searched for new elements by fractionating the oxides of rare-earths. Carl Gustaf Mosander s experiments indicated that pure ceria ores were actually contaminated with oxides of lanthanum, a new element. Mosander also fractionated the oxides of yttria into two new elements, erbium and terbium. In 1878 J. Louis Soret (1827—1890) and Marc Delafontaine (1837-1911), through spectroscopic analysis, found evidence of the element holmium, but it was contaminated by the rare-earth dysprosia. Since they could not isolate it and were unable to separate holmium as a pure rare-earth, they did not receive credit for its discovery. 

The values for the redox potential for the couple M3 + /M2+ have been estimated57 using a simple ionic model and available thermodynamic data. The results (Table 2) correlate closely with the ionization potentials for the M2+ ions, and are in good agreement with both chemical observations and other estimates obtained by spectroscopic correlations. Irreversible oxidation of terbium(m) to terbium(iv) in aqueous K2C03-K0H solutions has been observed electrochemically 58 the discovery of an intermediate of mixed oxidation state explains partly the reduction behaviour of terbium(iv) deposits. Praseodymium(iv) and terbium(iv) have also been detected in nitrate solutions. 

Terbium was discovered during the great element hunt of the 1840s. That hunt began with a lucky discovery made in 1787. A lieutenant in... 

Yttrium is one of four elements named for the same small town of Ytterby, Sweden. The other three elements are erbium, terbium, and ytterbium. The element was discovered in 1794 by Finnish chemist Johan Gadolin (1760—1852). The discovery of yttrium marked the beginning of 100 years of complicated chemical research that resulted in the discovery of 10 new elements. 

Yttrium asserted its individuality later. Whether Mosander obtained pure terbium or not remains unclear. Erbium had the same fate as didymium. And one more correction in the list of official discovery dates is necessary real yttrium was extracted by Mosander in 1843. Therefore, it is Mosander who stood at the cradle of REEs. 

The discovery in 1976 of magneto-optic materials based on the rare earth/transition metal (RE/TM) alloys (Choudhari et al., 1976) provided a practical material system for rewritable magneto-optic recording. These materials were amorphous and thus allowed acceptable signal-to-noise ratio to be obtained. Most commercial magneto-optic films today are based on terbium iron cobalt (TbFeCO). 

Discovery Carl Gustaf Mosander in Stockholm in 1842-43 found that Gadolin s yttrium, the first rare earth metal discovered, was composed of three elements. One was allowed to keep the name yttrium, while the two others became terbium and erbium. Thus these new elements also got their names from Ytterby. 

From Figure 17.3 it is clear that the history of discoveries falls into three different periods. The first, about 1800, was the time for the basic discoveries, yttrium and cerium the second, around 1840, resulted in four new elements, erbium, terbium, lanthanum and didymium. Not until the introduction of the spectroscopy in the middle of the 19 century and the development of improved separation techniques did the discoveries enter the third period, 1870-1910. Yet, the last REM, promethium, was not discovered until 1945. Some biographical information about the actual discoverers is given along with the different discovery descriptions below. 

This laboratory, described with such great insight by Johnston, certainly influenced the development of laboratories and examination techniques in other parts of Europe. The fact that the famous German chemist Friedrich Wohler frequently worked as a visiting scientist in the laboratory also contributed to its influence. Carl Gustaf Mosander s substantial work with rare earths around 1840 was also performed here. This led to the discovery of the elements lanthanum, didymium, erbium and terbium. 

As was the case for the previously discovered transuranium elements, element 97 was first produced via a nuclear bombardment reaction. In December 1949 ion-exchange separation of the products formed by the bombardment of Am with accelerated alpha particles provided a new electron-capture activity eluting just ahead of curium [1,2]. This activity was assigned to an isotope (mass number 243) of element 97. The new element was named berkelium after Berkeley, California, the city of its discovery, in a parallel manner to the naming of its lanthanide analog, terbium, after Ytterby, Sweden. The initial investigations of the chemical properties of berkelium were limited to tracer experiments (ion exchange and co-precipitation), but these were sufficient to establish the stability of Bk(iii) and the accessibility of Bk(iv) in aqueous solution and to estimate the electrochemical potential of the Bk(iv)/Bk(iii) couple [2,3]. 

One of the authors (PCJ) in Ytterby, Sweden, the site of the discovery of ytterbite and the town after which yttrium, terbium, erbium and ytterbium are named. 

---