Niobium naming

The main mineral source for some other metals can be complex. For example, the primary mineral sources for vanadium are vanadinite [Pb5(V04)3Cl] and camotite [K2(U02)2(V04)2 3 H2O], which is also a main mineral source for uranium. Vanadium, as we have seen, is also found in crude oil. No specific minerals contain the metal radium. Yet radium sometime substitutes for uranium within uranium-containing minerals. The small amount of radium that replaces uranium in camotite is also the major source of radium. Tantalum and niobium, named after the Greek god Tantalus and his daughter Niobe, always occur together in mixed deposits of columbite [Fe(Nb03)2l and tantalite [Fe(Ta03)2]. The minerals are mined together and the elements are later separated by recrystallization (see Section 12.4). 

Low Expansion Alloys. Binary Fe—Ni alloys as well as several alloys of the type Fe—Ni—X, where X = Cr or Co, are utilized for their low thermal expansion coefficients over a limited temperature range. Other elements also may be added to provide altered mechanical or physical properties. Common trade names include Invar (64%Fe—36%Ni), F.linvar (52%Fe—36%Ni—12%Cr) and super Invar (63%Fe—32%Ni—5%Co). These alloys, which have many commercial appHcations, are typically used at low (25—500°C) temperatures. Exceptions are automotive pistons and components of gas turbines. These alloys are useful to about 650°C while retaining low coefficients of thermal expansion. Alloys 903, 907, and 909, based on 42%Fe—38%Ni—13%Co and having varying amounts of niobium, titanium, and aluminum, are examples of such alloys (2). 

Niobium, discovered by Hatchett ia 1801, was first named columbium. In 1844, Rosed thought he had found a new element associated with tantalum (see Tantalum AND tantalum compounds). He called the new element niobium, for Niobe, daughter of Tantalus of Greek mythology. In 1949, the Union of Pure and Apphed Chemistry setded on the name niobium, but in the United States this metal is stiU known also as columbium. Sometimes called a rare metal, niobium is actually more abundant in the earth s cmst than lead. 

Good results are obtained with oxide-coated valve metals as anode materials. These electrically conducting ceramic coatings of p-conducting spinel-ferrite (e.g., cobalt, nickel and lithium ferrites) have very low consumption rates. Lithium ferrite has proved particularly effective because it possesses excellent adhesion on titanium and niobium [26]. In addition, doping the perovskite structure with monovalent lithium ions provides good electrical conductivity for anodic reactions. Anodes produced in this way are distributed under the trade name Lida [27]. The consumption rate in seawater is given as 10 g A ar and in fresh water is... 

One was Ekeberg s tantalum and the other he called niobium (Niobe was the daughter of Tantalus). Despite the chronological precedence of the name columbium, lUPAC adopted niobium in 1950, though columbium is still sometimes used in US industry. Impure niobium metal was first isolated by C. W. Blomstrand in 1866 by the reduction of the chloride with hydrogen, but the first pure samples of metallic niobium and tantalum were not prepared until 1907 when W. von Bolton reduced the fluorometallates with sodium. 

As was discussed in Chapter 4, tantalum and niobium dissolve in fluorine-containing solutions in the form of complex fluoride ions of two types, namely TaF727TaF6" and NbOF527NbF6 [61, 155, 171, 291]. The equilibrium between the complexes depends on the acidity of the solution and can be represented schematically as shown in Equations (139) and (140) for tantalum and niobium, respectively ... 

The main difference between the methods is usually related to the first step, namely fluorine substitution and precipitation of tantalum or niobium compounds. 

Name derived from Niobe, daughter of Tanatalus (Greek mythology) niobium and tantalum always occur together... 

Niobium (Nb, [Kr]4d45s1), name and symbol after the Greek mythological heroine Niobe (Tantalus daughter). Discovered (1801) by Charles Hatchett. The name niobium is now used in place of the original name columbium . 

There is also a great deal of interest in the production of single crystal piezo material from a mixture of lead, zirconium and niobium compounds (from which they get the name PZN). Such single crystal transducers would provide low loss, high strain, low modulus and have high coupling coefScients. At the time of writing these materials are not yet commercially available. 

ORIGIN OF NAME Niobium is named after the Greek mythological figure Niobe who was the daughter of Tantalus. Tantalus was a Greek god whose name is the source of the word "tantalize," which implies torture he cut up his son to make soup for other gods. 

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. 

However, the story does not end there. It was not until 1844 when Heinrich Rose (1795-1864) rediscovered the element by producing two similar acids from the mineral niobic acid and pelopic acid. Rose did not reahze he had discovered the old columbium, so he gave this new element the name niobium. Twenty years later, Jean Charles Galissard de Marignac (1817—1894) proved that niobium and tantalum were two distinct elements. Later, the Swedish scientist Christian Wilhelm Blomstrand (1826—1899) isolated and identified the metal niobium from its similar twin, tantalum. 

The element was discovered in 1801 by British chemist Charles Hatchett during analysis of a black mineral sample from the British Museum, originally sent in 1753 from Connecticut. He named the element columbium, after the country of its origin, Columbia (United States). In 1844, Rose announced the discovery of a new element which he named as niobium, in honor of Niobe, the daughter of Tantalus, the mythological Goddess of Tears. Later, it was established that Hatchett s columbium and Roses niobium were the same element. Both names remained in use for more than one hundred years. In 1949 at the Fifteenth International Union of Chemistry Congress held at Amsterdam, the name niobium was officially adopted as the international name. 

Tantalum was discovered by the Swedish chemist Anders Ekeberg in 1802, although for a long time after his discovery many chemists believed tantalum and niobium were the same element. In 1866, Marignac developed a fractional crystallization method for separation of tantalum from niobium. Ekeberg named the element in honor of Tantalus, who was Niobe s father in Greek mythology. 

This consideration also applies to 8-vertex clusters with interstitial atoms. The most spherical 8-vertex deltahedron, namely the bisdisphenoid (Eig. 1), appears to have too small a cavity for an interstitial transition metal. Plowever, the square antiprism has two fewer edges and can be partially flattened to make a puckered eight-membered ring, which can accommodate a transition metal in the center (Pig. 8). Known clusters of this type include M E8" (M = Cr [98], Mo [98], Nb [99] E = As, Sb n = 2,3 for Cr and Mo = 3 for Nb). The transition metal in such structures can be considered to be eight-coordinate with flattened square antiprismatic coordination. The Eg ring (E = As, Sb) can be considered formally to be an octaanion, isoelectronic with the common form of elemental sulfur, Sg. Thus in M Eg (M = Cr, Mo E = As, Sb), the central transition metal has the formal oxidation state of +6. Similarly in Nb Eg , the central niobium atom has its d formal oxidation state of +5. 

Although niobic and tantalic acids are extremely difficult to separate, Marignac finally succeeded, not only in separating them, but also in showing that niobium is both tri- and pentavalent, whereas tantalum always has a valence of five. The separation is based on the insolubility of potassium fluotantalate in comparison with potassium fluo-oxyniobate (12, 20). In the United States the element discovered by Hatchett used to be known as columbium, but in Europe most chemists prefer to use the name niobium which Heinrich Rose gave it. 

In 1877 the American mineralogical chemist J. Lawrence Smith named a mineral from North Carolina, a columbate of uranium, hatchetto-lite, because Hatchett s discovery of columbium (niobium) was clear, precise, and well made out, and has never been controverted (35). 

Compound Semiconductors. The niobium-based superconducting compounds lead us naturally into another use for intermetallics—namely, semiconductors. This topic, too, was introduced earlier in this chapter (cf. Section 6.1.1.4 and 6.1.1.5), and we shall build upon those principles here to describe the semiconducting properties of compounds, ceramics, and glasses. The classification of intermetallics as ceramics... 

The names of the elements are given in the table on page 262. t Alternatively, niobium (Nb). 

Recently, there has been a growing interest into niobium- and tantalum-containing molecular sieves. The introduction of niobium into mesoporous molecular sieves has been studied by Ziolek et al [3,4], while Antonelli and Ying reported the synthesis of mesoporous niobium oxide [5], The synthesis and characterization of niobium- and tantalum-containing silicalite-1 (NbS-1 and TaS-1) was published recently [6,7,8] and some evidence has been presented for isomorphous substitution [6,8] of Nb and Ta into the silicalite-1 framework. The synthesis of NbS-2 (MEL) [9] and a new molecular sieve named NbAM-11 have been reported as well [10],... 

Niobium is also known as columbium. The latter name has always been preferred in America, and is retained, no doubt, out of patriotism. In England the name columbium was employed by the Chemical Society from 1904 to 1923 inclusive in 1924 the name niobium was readopted. On the Continent the element has been more consistently referred to by the various translations of niobium. 

Hydrates of Niobium Pentoxide. Colloidal Niobium Pentoxide.— Niobium pentoxide does not combine directly with water to form acids of definite composition. Two hydrates of the oxide, namely, 3Nb20s.4H20 and 3Nb205.7H20, have been reported,8 but their existence is very improbable. The term nioUe acid, is applied to the more or less hydrated pentoxide. When niobium pentachloride or niobium oxytriehloride, NbOCla, is hydrolysed with excess of water there is produced a white, amorphous, hydrated gel, which can also be obtained by the action of sulphuric acid or hydrochloric acid on alkali niobates 10 the precipitate is redissolved by excess of acid. Similar solutions axe... 

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