Yttrium Ferrites

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. 

Small amounts of Y or La are used to dope BaTiC>3 which is the main component of all PTCs (positive temperature coefficient). Demand for PTC thermistors is high. Yttrium iron garnets are used in soft ferrites at very high frequencies (microwave region) for radar equipment. 

Work on one particular ferritic steel, Fecralloy, for fabrication of catalyst substrates was pioneered by the United Kingdom Atomic Energy Authority at Harwell and Johnson Matthey, in collaboration with Resistalloy, which developed technology for producing thin strip [32]. This and related alloys, in addition to iron, chromium, and aluminum, contain low levels of elements such as yttrium (0.1-3.0%), thought to enhance the protective properties of the surface alumina layer. Alumina forms by the oxidation of bulk... 

EINECS 231-174-8 Yttrium Yttrium-89. Metallic element nuclear technology, iron and other alloys, deoxidizer for vanadium and other nonferrous metals, microwave ferrites, coating on high-temperature... 

The garnet ferrites are the basis of materials for many high-technology devices for magnetooptical, microwave and memory applications. These ferrites have thus been extensively studied as ceramics, single crystals, thin and epitaxial films, etc. The prototype, yttrium iron garnet or YIG has also been used for many fundamental studies. 

Metselaar, R. Huyberts, M. A. H. (1973). The stoichiometry and defect structure of yttrium iron garnet and the nature of the centres active in the photomagnetic effect. Journal of Physics and Chemistry of Solids, 34,2257-63. Miyahara, S. Ohnishi, H. (1956). Cation arrangement and magnetic properties of copper ferrite-chromite series. Journal of the Physical Society, Japan, 11, 1296-7. 

The papers [79,80] give consideration to the radiation tolerance of ferrite steel hardened with yttrium oxide (YjOj) particles of 20 nm. Two types of radiation treatment were used, in particular irradiation with helium ions that results in the formation of barely point defects and bombardment with high-energy (150 keV) iron ions. In the latter case, defects were mainly formed in displacement cascades, whose size ranges within 2-3 nm. It has been established that the changes in the distribution of dispersed phase and its component composition were not observed whatever methods were used to create defects. 

Extension of the microemulsion reaction method to complex oxides has been explored for a wide variety of materials, including aluminosilicate zeolite [45,108] ferrites [109], mullite [110], barium titanate [111,112], and various perovskite-type mixed oxides [112,113], yttrium-iron garnets (YIGs) [114,115], and high TV superconducting oxides [116-120]. 

Ferrous chloride ferrite ceramics raw material Manganese dioxide ferrite mfg., electronics Nickel oxide (ous) ferrites, electronic industry Iron oxide black ferrites, microwave Yttrium... 

Talbe 2. The comparison of some microwave ME coupling results in different multiferroic heterosturcutres. (YIG yttrium iron garnet ferrite GO gadolinium gallium garnet)... 

Yttrium is used as an alloying additive in magnesium alloys. It is used in ferrite and garnet bubble devices, in catalysts, in superalloys as dispersant, in ceramic capacitors, and for the stabilization of zirconia. Finally, YBa Cu,0 is the precursor of superconductive oxides at room temperature. 

Ferrite A ceramic material made of powdered and compressed ferric oxide, plus other oxides (mainly cobalt, nickel, zinc, yttrium-iron, and manganese). These materials have low eddy current losses at high frequencies. 

This magnetic technique was used by Okamura and Shimoizaka ( ) to study the reaction kinetics of wet-chemically prepared nickel ferrite and by Economos and Clevenger ( ) to study the reaction of dry-mixed nickel oxide and iron oxide powders. Rubinchik et al. ( ) detected magnetically the presence of yttrium-iron garnet in the reaction between Fe203 and Y2O3. 

Strontium cobalt ferrites are good mixed conductors but are more suitable to be used as cathodes due to their p-type conduction. Pervoskite gaUates/niobates/barium cerate and chromium-doped lanthanum-strontium ferrite have also been studied as the anode material. Although the gaUates and niobates exhibit low conductivity, they exhibit good compatibihty with the LSGM electrolytes. The conductivity of yttrium-doped barium cerates increases by increasing yttrium content. For barium cerates, the increase in electronic conduction due to the reduction of cerium at low... 

Magnetic nanoparticles showing Faraday rotation effect, and/or Kerr effect can be of interest in the fabrication of switches and devices. Size dependant transmittance and Faraday rotation have been found in maghemite ferrofluids and ferrite films." Multilayered assemblies of yttrium garnet nanoparticles show magnetization-induced second harmonic generation (Kerr effect)." In metal/PMMA nanocomposites, the main absorption band narrows and additional peaks appear when decreasing the particle size." ... 

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