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Tantalates

Gr. Tantalos, mythological character, father of Niobe) Discovered in 1802 by Ekeberg, but many chemists thought niobium and tantalum were identical elements until Rowe in 1844, and Marignac, in 1866, showed that niobic and tantalic acids were two different acids. The early investigators only isolated the impure metal. The first relatively pure ductile tantalum was produced by von Bolton in 1903. Tantalum occurs principally in the mineral columbite-tantalite. [Pg.132]

Simple ABO compounds in addition to BaTiO are cadmium titanate [12014-14-17, CdTiO lead titanate [12060-00-3] PbTiO potassium niobate [12030-85-2] KNbO sodium niobate [12034-09-2], NaNbO silver niobate [12309-96-5], AgNbO potassium iodate [7758-05-6], KIO bismuth ferrate [12010-42-3], BiFeO sodium tantalate, NaTaO and lead zirconate [12060-01 -4], PbZrO. The perovskite stmcture is also tolerant of a very wide range of multiple cation substitution on both A and B sites. Thus many more complex compounds have been found (16,17), eg, (K 2 i/2) 3 ... [Pg.203]

There is often a wide range of crystalline soHd solubiUty between end-member compositions. Additionally the ferroelectric and antiferroelectric Curie temperatures and consequent properties appear to mutate continuously with fractional cation substitution. Thus the perovskite system has a variety of extremely usehil properties. Other oxygen octahedra stmcture ferroelectrics such as lithium niobate [12031 -63-9] LiNbO, lithium tantalate [12031 -66-2] LiTaO, the tungsten bron2e stmctures, bismuth oxide layer stmctures, pyrochlore stmctures, and order—disorder-type ferroelectrics are well discussed elsewhere (4,12,22,23). [Pg.205]

Occurrence. Niobium and tantalum usually occur together. Niobium never occurs as the metal, ie, ia the free state. Sometimes it occurs as a hydroxide, siUcate, or borate most often it is combiaed with oxygen and another metal, forming a niobate or tantalate ia which the niobium and tantalum isomorphously replace one another with Htde change ia physical properties except density. Ore concentrations of niobium usually occur as carbonatites and are associated with tantalum ia pegmatites and alluvial deposits. Principal niobium-beariag minerals can be divided iato two groups, the titano- and tantalo-niobates. [Pg.22]

DTGS = deuterated triglycine sulfate KRS — 5 = mixed thallium bromide-iodide LT = lithium tantalate MCT = mercury cadmium telluride and OPO = optical parametric oscillator. [Pg.313]

Tantalic Acid and Tantalates. Tantahc acid [75397-94-3] Ta20 is the name of the white insoluble precipitate formed by hydrolysis... [Pg.333]

Possibly the most serious nutrition problem in the United States is excessive food consumption, and many people have experimented with fad diets in the hope of losing excess weight. One of the most popular of the fad diets has been the high-protein, high-fat (low-carbohydrate) diet. The premise for such diets is tantalizing because the tricarboxylic acid (TCA) cycle (see Chapter 20) is the primary site of fat metabolism, and because glucose is usually needed to replenish intermediates in the TCA cycle, if carbohydrates are restricted in the diet, dietary fat should merely be converted to ketone bodies and excreted. This so-called diet appears to work at first because a low-carbohydrate diet results in an initial water (and weight) loss. This occurs because... [Pg.585]

Most niobates and tantalates, however, are insoluble and may be regarded as mixed oxides in which the Nb or Ta is octahedrally coordinated and with no discrete anion present. Thus KMO3, known inaccurately (since they have no discrete MO3 anions) as metaniobates and metatantalates, have the perovskite (p. 963) stmcture. Several of these perovskites have been characterized and some have ferroelectric and piezoelectric properties (p. 57). Because of these properties, LiNb03 and LiTa03 have been found to be attractive alternatives to quartz as frequency filters in communications devices. [Pg.987]

Fluor-jod, n. iodine fluoride, -kalium, n. potassium fluoride, -kalzium, n. calcium fluoride, -kiesel, m. silicon fluoride, -kie-selsaure,/. fluosilicic acid, -kohlenstoff, m. carbon fluoride, -lithium, n. lithium fluoride. -metall, n. metallic fluoride, -natrium, n. sodium fluoride, -phosphat, n. fluophosphate. -phosphor, m. phosphorus fluoride, -salz, n. fluoride, -schwefel, m. sulfur fluoride, -selen, n. selenium fluoride, -silber, n. silver fluoride, -silikat, n. fluo-silicate. -silizium, n. silicon fluoride, -sili-ziumverbindung, /. fluosilicate. -tantal-sMure, /. fluotantalic acid, -tellur, n. tellurium fluoride, -titan, n. titanium fluoride, -toluol, n. fluorotoluene, fluotoluene. [Pg.160]

Tantal, n. tantalum, -erz, n. tantalum ore, specif, tantalite. tantalig, a. tantalous, tantalisch, a. of tantalum, tantalic. Tantal-lampe, /. tantalum lamp, -ozyd, n. [Pg.440]

Meyll Shpeydel, Collection Niobi I Tantal, Ed. O. P. Kolchina, 565-571 (1960)... [Pg.863]

Since niobates and tantalates belong to the octahedral ferroelectric family, fluorine-oxygen substitution has a particular importance in managing ferroelectric properties. Thus, the variation in the Curie temperature of such compounds with the fluorine-oxygen substitution rate depends strongly on the crystalline network, the ferroelectric type and the mutual orientation of the spontaneous polarization vector, metal displacement direction and covalent bond orientation [47]. Hence, complex tantalum and niobium fluoride compounds seem to have potential also as new materials for modem electronic and optical applications. [Pg.9]

Dioxytetrafluoroniobates (-tantalates) of alkali metals for the general M3Me02F4 type also belong to the family characterized by X Me=6. Structural characteristics of the compounds are collected in Table 26. [Pg.78]

Regarding dioxytrifluoroniobates (-tantalates) of alkali metals, information on the synthesis of K2Nb02F3 and K2Ta02F3 is available in [213] and [214], respectively. [Pg.89]

Known oxyfluoroniobates (-tantalates) with compositions that correspond to X Me = 3 crystallize in typical structures of ReC>3, pyrochlore, and hexagonal and tetragonal tungsten bronze. Table 35 presents structural parameters of such compounds. [Pg.101]

The second group is the group of oxyfluorides that are derived from ferroelectric oxides by means of fluorine-oxygen substitution. The basic oxides are usually perovskite, tetragonal tungsten bronze, pyrochlore, lithium tantalate etc. [400]. [Pg.219]

Concentrates of columbate-tantalate are most suitable for processing and are most frequently used in the production of tantalum, niobium and their compounds. [Pg.253]


See other pages where Tantalates is mentioned: [Pg.385]    [Pg.385]    [Pg.558]    [Pg.574]    [Pg.575]    [Pg.910]    [Pg.960]    [Pg.150]    [Pg.523]    [Pg.193]    [Pg.292]    [Pg.25]    [Pg.137]    [Pg.323]    [Pg.333]    [Pg.314]    [Pg.302]    [Pg.344]    [Pg.480]    [Pg.480]    [Pg.72]    [Pg.104]    [Pg.440]    [Pg.1149]    [Pg.1746]    [Pg.342]    [Pg.681]    [Pg.2]    [Pg.5]    [Pg.74]    [Pg.75]    [Pg.79]    [Pg.222]   
See also in sourсe #XX -- [ Pg.987 ]

See also in sourсe #XX -- [ Pg.6 , Pg.186 , Pg.199 ]

See also in sourсe #XX -- [ Pg.987 ]

See also in sourсe #XX -- [ Pg.655 ]

See also in sourсe #XX -- [ Pg.41 ]

See also in sourсe #XX -- [ Pg.756 ]

See also in sourсe #XX -- [ Pg.110 ]

See also in sourсe #XX -- [ Pg.790 ]

See also in sourсe #XX -- [ Pg.252 , Pg.253 , Pg.254 ]




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A-Site-Deficient Titanates, Niobates and Tantalates

Ammonium tantalate

Barium strontium tantalate

Barium tantalate

Cobalt tantalate

Detectors lithium tantalate

Different Phases of Fluorido-Tantalates

Fabrication lithium tantalate

Ferroelectric strontium bismuth tantalate

Fluorido-tantalate

Hexa-tantalates

Iron tantalates

Lithium tantalate

Lithium tantalate , piezoelectric

Lithium tantalate , piezoelectric properties

Lithium tantalate decomposition

Magnesium tantalates

Mercurous tantalate

Mg-doped barium tantalate

Mixed metal oxides tantalates

Perovskite Niobates and Tantalates

Potassium fluorido-oxido-tantalate phases

Potassium tantalate

Potassium tantalates

Silver tantalate

Sodium tantalate

Sodium tantalates

Strontium bismuth tantalate

Subject tantalates

Tantalate

Tantalate

Tantalate , hexabromo

Tantalate , hexabromo potassium

Tantalate alkoxides

Tantalate powders

Tantalate pyrochlores

Tantalates Reduction

Tantalates Tantalic acid

Tantalates and Niobates

Tantalates, alkali

Tantalic acid

Tantalic acid anhydride

Tantalic chloride

The Tantalate Complex TaO

The Tantalate Complexes

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