Magnetic yttrium

The heavy mineral sand concentrates are scmbbed to remove any surface coatings, dried, and separated into magnetic and nonmagnetic fractions (see Separation, magnetic). Each of these fractions is further spHt into conducting and nonconducting fractions in an electrostatic separator to yield individual concentrates of ilmenite, leucoxene, monazite, mtile, xenotime, and zircon. Commercially pure zircon sand typically contains 64% zirconium oxide, 34% siUcon oxide, 1.2% hafnium oxide, and 0.8% other oxides including aluminum, iron, titanium, yttrium, lanthanides, uranium, thorium, phosphoms, scandium, and calcium. 

So-called hexagonal ferrites such as BaFe -Oi9 are ferrimagnetic and are used to construct permanent magnets. A third type of ferrimagnetic mixed oxides are the garnets, Mj FejOjj, of which the best known is yttrium iron garnet (YIG) used as a microwave filter in radar. 

In yttrium iron garnet Y3Fe5012 ( YIG ) a ferrimagnetic coupling (superexchange) is active between the octahedral and the tetrahedral sites. Since the tetrahedral sites are in excess, the magnetic moments do not compensate each other. The magnetic properties can be varied by substitution of yttrium by lanthanoids. 

Silver-colored, ductile metal that is attacked slowly by air and water. The element exhibits interesting magnetic properties. Found in television tubes. Laser material such as YAG (yttrium-aluminum garnet) doped with holmium (as well as chromium and thulium) can be applied in medicine, especially in sensitive eye operations. 

Garnets are important gems, abrasives, microwave systems components, magnetic bubble memories, and laser hosts. For the latter, yttrium aluminum garnet is the most important. It also plays an important role in aircraft turbines where it forms a protective coating on the turbine blades. 

In [20], the composition of the citrate precursor of CoFe204 is proposed as Co3Fe604(C6H607)8-6H20, i.e., two protons are detached from each molecule of citric acid, and the complex compound could be classified as an acidic salt. Distinct signatures of complex formation are obtained by means of infrared (IR) spectroscopy and nuclear magnetic resonance (NMR) for citrate complexes of iron and yttrium, potential precursors of YFe04 and... 

DAS has rivb° 1.6156 and d25° 1.3992 the nuclear magnetic resonance spectrum has a singlet at 8.83 r and an A2B2 pattern at 2.62 r. Although DAS is very oxygen-sensitive, it is readily stored in sample bottles with serum caps. Complexes of many metals have been prepared exceptions include scandium, yttrium, lanthanum, and zinc. 

Among the best-known garnets Y3Fe2Fe3012 (Y3Fe5012 yttrium-iron garnet YIG) for its magnetic properties and applications, Y3A15012 (YAG, important laser host material). 

Below is a brief review of the published calculations of yttrium ceramics based on the ECM approach. In studies by Goodman et al. [20] and Kaplan et al. [25,26], the embedded quantum clusters, representing the YBa2Cu307 x ceramics (with different x), were calculated by the discrete variation method in the local density approximation (EDA). Although in these studies many interesting results were obtained, it is necessary to keep in mind that the EDA approach has a restricted applicability to cuprate oxides, e.g. it does not describe correctly the magnetic properties [41] and gives an inadequate description of anisotropic effects [42,43]. Therefore, comparative ab initio calculations in the frame of the Hartree-Fock approximation are desirable. 

Swedish physicist, astronomer, and spec-troscopist. He mapped the spectra of yttrium, erbium, didymium, lanthanum, scandium, thulium, and ytterbium, and in 1866 wrote a histoncal review of spectrum analysis. He also studied the magnetic properties of iron and iron ores. 

Various substitution studies (171-173) were conducted in the early stages of research on these new oxide superconductors. One most dramatic result was the facile substitution of other (magnetic) lanthanide ions for yttrium in the VUI-coordinated site of the structure. The incorporation of these magnetic ions had no effect on the superconductivity nor the Tc of the material— quite astounding, since the presence of magnetic ions in superconductors was previously believed to destroy the phenomenon entirely Table 13 presents several examples of such substituted compounds. 

To a 50 mL, flame dried round-bottomed flask equipped with a magnetic stirrer bar and a 3-way tap with argon balloon containing yttrium tri-Ao-propoxide (1.07 g, 4.0 mmol) at 0°C was slowly added freshly distilled tetrahydrofuran (20 mL) over 30 min. After stirring for 30 min at 0 °C, the mixture was warmed to room temperature. The stirring was continued for 1 h at room temperature to afford 0.2 M yttrium tri-wo-propoxide solution in tetrahydrofuran. 

Permanent magnets having properties several times superior to any other known materials were developed in 1967. Praseodymium, yttrium, samarium, lanthanum, and cerium are alloyed with cobalt in the range... 

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