Niobium History

The mechanical properties of niobium are dependent on the previous history of the material and the manufacturer should be consulted if these properties are likely to be critical. Physical and some typical mechanical properties are set out in Tables 5.10 and 5.11. 

Apart from structures that are built of slabs, modular structures that can be constructed of columns in a jigsawlike assembly are well known. In the complex chemistry of the cuprate superconductors and related inorganic oxides, series of structures that are described as tubular, stairlike, and so on have been characterized. Alloy structures that are built of columns of intersecting structures are also well known. Structures built of linked columns, tunnels, and intersecting slabs are also found in minerals. Only one of these more complex structure types will be described, the niobium oxide block structures, chosen as they played a significant role in the history of nonstoichiometry. 

Niobium has a rather confusing history, starting in 1734 when the first governor of Connecticut, John Winthrop the Younger (1681—1747), discovered a new mineral in the iron mines of the New England. He named this new mineral columbite. Although he did not know what elements the mineral contained, he believed it contained a new and as yet unidentified element. Hence, he sent a sample to the British Museum in London for analysis. It seems that the delivery was mislaid and forgotten for many years until Charles Hatchett (1765-1847) found the old sample and determined that, indeed, a new element was present. Hatchett was unable to isolate this new element that he named columbium, which was derived from the name of Winthrop s mineral. 

History.—The discovery of niobium is intimately connected with that of tantalum, firstly because these metals are consistently associated together in their natural ores, and secondly, because their separation from one another has proved an extremely difficult matter. Indeed, the chemistry of these elements is so closely parallel that considerable time elapsed before their separate identities were definitely established. 

Fig. 7.2. Electron temperature, density and Nb31+ X-ray brightness time histories for an L-mode discharge with niobium injection at 0.5 s...

Niobium has a very interesting history. It was discovered by English chemist Charles Hatchett (1765—1847) in 1801. Hatchett found the element in a stone sent from North America. He named the element colum-bium. For years, scientists argued about the correct name for the element. Some still call the element columbium, although the official name is now niobium. 

They had had to work for nearly half a year before they could present their tentative conclusions in a short letter to the London journal Nature. Briefly, the letter reported the first in history artificial synthesis of a new chemical element. This was element 43 the futile search for which on Earth wasted so much efforts of scientists from many coimtries. Professor E. Lawrence from the University of California at Berkley gave the authors a molybdenum plate irradiated with deutrons in the Berkley cyclotron. The plate exhibited a high radioactivity level which could hardly be due to any single substance. The half-life was such that the substances could not be radioactive isotopes of zirconium, niobium, molybdenum, and ruthenium. Most probably they were isotopes of element 43. 

Sir Hans Sloane (1660-1753) in London was an active man of science, president of the Royal Society and editor of the distinguished journal Philosophical Transactions. He was also an interested collector. Books, pictures, coins and minerals from his collection were placed at the disposal of the British Museum. Sir Hans had close contact with John Winthrop Jr in Connecticut, who in 1734 was elected as a member of the Royal Society. John donated more than six hundred specimens of minerals from New England, which were incorporated in the mineralogical collection of the British Museum. This turned out to be of great importance in the history of element discoveries. At the beginning of the 19 century the element niobium, or columbium as it was called, was discovered in the mineral collection from New England. 

The history of element discoveries shows notable similarities for niobium and vanadium as shown in Table 22.1. 

Niobium and Tantalum Minerals 557 Table 22.1 Similarities in the history of vanadium and niobium discoveries... 

---