Yttrium

“ The yttrium elements can be separated from the cerium metals, and the latter from one another, by taking advantage of the differences of solubility shown by the potassium double carbonates. If a concentrated solution of the salts in potassium carbonate solution be fractionally diluted with water, the cerium elements separate in the order: lanthanum, praseodymium, cerium, neodymium, and samarium; the more soluble yttrium compounds remain in the solution. Thorium forms double alkali carbonates which are very readily soluble in excess of alkali carbonate ”

“ It will be seen that, with the exception of scandium and yttrium, the metals of the cerium and yttrium groups become less electropositive as the atomic weight increases.
This arrangement is obtained by ascertaining the order in [118] which the various hydroxides are precipitated from a solution by gradual addition of a dilute solution of a strong base. The weakest base is precipitated first, and the strongest last; those intermediate in strength are thrown down in ascending order of strength. ”

“ The nature of the mineral used for the extraction will, as a rule, afford useful information. It is known that in some minerals the cerium group, in others the yttrium group, predominates more or less completely; certain minerals, also, are known to be rich in elements of one or another subgroup. An approximate knowledge of the relative [148] proportions of the cerium, terbium, and yttrium groups will be afforded by a rough double sulphate separation; thorium, zirconium, and scandium come down with the cerium earths. ”

“ The phthalates of the yttrium group have been found to be very valuable for purposes of separation by Meyer and Wuorinen. [172] The salts are readily obtained in solution by shaking together cold aqueous suspensions of the rare earth hydroxides, and phthalic acid; the clear solutions when warmed become cloudy, the organic salts hydrolysing very easily, with separation of the hydroxides. The most positive elements naturally remain longest in the solution, the weakly basic oxides accumulating in the first precipitates. ”

“ The trivalency of yttrium, which makes us now represent its oxide as Y2O3 instead of as YO, was also foreseen (in 1870) by the periodic law, and it has now become so probable that Clève, and all other subsequent investigators of the rare metals, have not only adopted it, but have also applied it without any new demonstration to substances so imperfectly known as those of the cerite and gadolinite group, especially since Hillebrand determined the specific heats of lanthanum and didymium and confirmed the expectations suggested by the periodic law. ”

“ In the first group is scandium oxide with equivalent 45, in the second, yttrium oxide 76, in the third, lanthanum, cerium, didymium, and samarium oxides with equivalent about 110, and, in the fourth, erbium, ytterbium, and thorium oxides with equivalent about 131. The common difference of period is nearly 45. And if we ascribe the type R2O3 to all the oxides—that is, if we triple the weight of the equivalent of the oxide—we shall obtain a difference of the groups nearly equal to 90, which, for two atoms of the metal, forms the ordinary periodic difference of 45. ”

“ The second class contains the yttrium and cerium metals, with zirconium and thorium; the technical importance of these elements is due chiefly to the use of their oxides in illumination, to a small extent in Nernst lamps, and to a much greater extent in the so-called Incandescent Lighting. The manufacture of incandescent mantles [487] is a large and ever-extending industry, intimately bound up with the older process of coal-distillation, with its innumerable ramifications ”

“ The rare earth iodates are soluble in nitric acid, the solubility increasing as the electropositive character of the element becomes stronger. A method for the purification of yttrium has recently been based upon this property of the iodates, whilst the fact that thorium iodate is completely insoluble in nitric acid allows of the easy separation and estimation of thorium in minerals or mixtures containing rare earth elements. ”

“ Symbol Y. Atomic weight, 89. [Written also ittrium.]
Associated with yttrium are certain rare elements, as erbium, ytterbium, samarium, etc., which are separated in a pure state with great difficulty. They are studied by means of their spark or phosphorescent spectra. Yttrium is now regarded as probably not a simple element, but as a mixture of several substances.
Yt`tro-ce"rite (?) , n. (Min.) A mineral of a violet-blue color, inclining to gray and white. It is a hydrous fluoride of cerium, yttrium, and calcium. ”

“ After the relatively simple separation from foreign elements has been accomplished, the enormously greater difficulty of separating the elements from one another has to be encountered. So great is this difficulty, by reason of the fact that, with the sole exception of cerium, the elements show no variation in property sufficient to allow of the use of ordinary analytical methods, that even at the present day it is extremely doubtful if all the elements in the yttrium group are known to us. ”

“ Absorption in the visible region of the spectrum is observed only with those rare earth compounds which are coloured, and is of value, therefore, chiefly for identification in the case of praseodymium and neodymium among the cerium elements, and of erbium among the yttrium metals; these give characteristic absorption bands, even in dilute solution. ”

“ In yttrium, on the proto level, a 110 and b 63 both escape from the funnel, and behave as in scandium. The ovoids and "cigars," set free on the meta level, behave as in boron. The central globe breaks up as in gold (pp. 49 and 50) , four quartets being set free instead of two quartets and two triplets. We have only to consider e 8 and d 20 (Plate XI, 4) . E 8 is a tetrahedral arrangement of duads on the meta level, set free as duads on the hyper. D 20 is an arrangement of pairs of duads at the angles of a square-based pyramid on the meta, and again free duads on the hyper. ”

“ Analyses of material from different localities exhibit wide variations in chemical composition. In addition to uranium oxides, there are thorium, cerium (and lanthanum) , yttrium and lead oxides, each varying in amount from a trace up to 10%. Calcium, iron, magnesium, manganese, silica, water, &c., are also present in small amounts. ”

“ Gallium, indium, and thallium belong to the uneven series, and there should be elements of the even series in group III. corresponding with calcium, strontium, and barium in group II. These elements should in their oxides R2O3 present basic characters of a more energetic kind than those shown by alumina, just as calcium, strontium, and barium give more energetic bases than magnesium, zinc, and cadmium. Such are yttrium and ytterbium, which occur in a rare Swedish mineral called gadolinite, and are therefore termed the gadolinite metals. ”

“ The metal has probably not been obtained in the pure state; impure yttrium has been obtained by Winkler [402] by the action of magnesium on the oxide, and by Cleve [403] by the action of sodium on a mixture of the chloride with common salt, and by electrolysis of the mixture of fused chlorides. It is described as a greyish metal, resembling iron in appearance; it oxidises in the air and readily decomposes boiling water. The hydroxide is thrown down as a gelatinous precipitate by alkalies; ammonia throws down basic salts, but in presence of hydrogen peroxide an hydrated peroxide is obtained. ”

“ This is a recently discovered mineral closely related to samarskite and yttrotantalite (q.v.) . It is essentially a columbate [64] of yttrium metals, lead and uranium, with water, ferrous oxide, titanium dioxide, stannic oxide, alumina, lime, and cuprous oxide. The formula given is R ́ ́2Cb2O7,R ́ ́ ́ ́4 (Cb2O7) 3, where R ́ ́ = (Fe,Pb,Ca,UO) , and R ́ ́ ́ = Al and yttria metals, with isomorphous (?) metatitanate. The mineral is radio-active, and gives considerable quantities of gas on being heated with sulphuric acid (carbon dioxide 0·19, helium and nitrogen 0·22 per cent.) . ”

“ Until lately such bodies passed muster as elements. They had definite properties, chemical and physical; they had recognized atomic weights. If we take a [pg 599] pure dilute solution of such a body, yttrium for instance, and if we add to it an excess of strong ammonia, we obtain a precipitate which appears perfectly homogeneous. But if instead we add very dilute ammonia in quantity sufficient only to precipitate one-half of the base present, we obtain no immediate precipitate. ”

“ Let us, then, modify this conception. For “element” read “elementary group”—such elementary groups taking the place of the old elements in the periodic scheme—and the difficulty falls away. In defining an element, let us take not an external boundary, but an internal type. Let us say, e.g., the smallest ponderable quantity of yttrium is an assemblage of ultimate atoms almost infinitely more like each other than they are to the atoms of any other approximating element. It does not necessarily follow that the atoms shall all be absolutely alike among themselves. ”

“ Germanium is a greyish-white, lustrous metal of sp.gr. 5.5., melting at about 900°, and resembling silicon and tin in its general chemical relations.
Dysprosium, europium, gadolinium, lutecium, neodymium, praseodymium, samarium, thulium, and ytterbium (neoytterbium) belong, like scandium, to the group of the so-called rare earth metals. These substances have been detected in a great variety of minerals, many of which are extremely rare. The elements most frequently occur in nature associated with yttrium, cerium, thorium, and zirconium. ”

“ Didymium also gives one colourless oxide, Di2O3, which is capable of forming salts (of a lilac colour) , and another, according to Brauner, Di2O5 which is dark brown and does not form salts, so far as is known, and (like ceric oxide) acts as an oxidising agent, like the higher oxides of tellurium, manganese, lead, and others. Lanthanum, yttrium, and many others are not capable of such oxidation. The presence of the higher oxides may be recognised by ignition in a stream of hydrogen, by which means the higher oxides are reduced to the lower, which then remain unaltered. ”

“ Yttrium, it′ri-um, n. a rare metal obtained as a blackish-gray powder, and contained in a few minerals in which there are usually also present compounds of one or more other rare metals, such as cerium, didymium, erbium, and lanthanum.—n. Ytt′ria, its oxide, a yellowish-white powder.—adjs. Ytt′ric; Yttrif′erous; Ytt′rious.—ns. Ytt′ro-cē′rite, a violet mineral found embedded in quartz, a fluoride of yttrium, cerium, and calcium; Ytt′ro-col′umbite, -tan′talite, a brownish mineral found at Ytterby, a tantalate of yttrium, uranium, and iron, with calcium. ”

“ Voight and Wiechert (Wied. Ann. 67, p. 345) detected the double refraction produced when light travels through a substance exposed to a magnetic field at right angles to the path of the light; this result had been predicted by Voight from theoretical considerations. Jean Becquerel has made some very interesting experiments on the effect of a magnetic field on the fine absorption bands produced by xenotime, a phosphate of yttrium and erbium, and tysonite, a fluoride of cerium, lanthanum and didymium, and has obtained effects which he ascribes to the presence of positive electrons. ”

“ The oxides, R2O3, though perfectly white, are coloured yellow or brown by the faintest traces of thulium. They are attacked by acids only slowly in the cold, but dissolve readily on warming; lutecia is slightly the less strongly basic. The chlorides crystallise with six molecules of water, and are extremely soluble and deliquescent; when heated in a stream of hydrogen chloride, they form oxychlorides of the type ROCl. The platinocyanides crystallise with 18 molecules of water, and have the characteristic appearance of the analogous compounds of the yttrium elements. ”

“ YTTERBIUM (Neo-Ytterbium) [symbol, Yb; atomic weight, 172.0 (O = 16) ] , a metallic chemical element belonging to the rare earth group. Mixed with scandium it was discovered by Marignac in gadolinite in 1878 (see Rare Earths) . The oxide, Yb2O3, is white and forms colourless salts; the crystallized chloride, YbCl3·6H2O, forms colourless, deliquescent crystals ”

“ The oxide is the most strongly basic of all the yttria earths; in the basicity methods of separation, therefore, it collects in the end fractions, and is easily separated from the erbia and ytterbia earths by the nitrate fusion and similar processes. The terbia earths, however, which are comparable to it in basic strength, cannot be easily separated by such methods ”

“ Egan and Balke [415] have recently found the ratio Yt2O3 : 2YtCl3 to be very suitable as a basis for atomic weight determinations; the oxide is converted into the anhydrous chloride in a quartz flask. In a preliminary experiment, they obtain as a mean of three consistent determinations the provisional value 90·12; the yttria employed was considered to contain not more than one-half per cent. of erbia.
[415] J. Amer. Chem. Soc. 1913, 35, 365.
Recent work by Meyer and his co-workers [416] indicates that the accepted value is too high. ”

“ The magnetic power of iron is conspicuous, whatever be its chemical condition; indeed, the magnetic properties of substances, though varying with temperature, seem not to be greatly affected by other physical changes. Colour, absorptive power for heat or light rays, and a few other properties are also often the same in liquids and gases. Iodine and bromine possess a deep colour whenever they are chemically uncombined. Nevertheless, we can seldom argue safely from the properties of a substance in one condition to those in another condition. ”