across) and UI-21 (1.5 cm across). UI-3 is a websterite, composed of augite (gray), orthopyroxene (white) and spinel (brown); at the top is the host basalt. UI-21 is a spinel lherzolite; spinel is brown, other phases near-white. MINERALOGY DETERMINATIONS BY CHEMIN XRD, TESTED ON ULTRAMAFIC ROCKS (MANTLE XENOLITHS). A. H. Treiman, K. L. Robinson, D. F. Blake, and D. Bish. Lunar and Planetary Ins...

Lithium-ion batteries have attracted widespread attention as new energy storage materials, and electrode especially cathode are the main factors affecting electrochemical performance of lithium-ion batteries, they also determine cost preparing batteries. In recent years, there been a lot researches on selection modification materials based to continuously optimize This article introduces resear...

Nanostructured Cu(x)Zn(1-x)Al(2)O(4) with a Cu:Zn ratio of ¼:¾ has been prepared by a microwave-assisted hydrothermal synthesis at 150 °C and used as a precursor for Cu/ZnO/Al(2)O(3)-based catalysts. The spinel nanoparticles exhibit an average size of approximately 5 nm and a high specific surface area (above 250 m(2) g(-1)). Cu nanoparticles of an average size of 3.3 nm can be formed by reduct...

We report on the intriguing evolution of the dynamical spin correlations of the frustrated spinel ZnMn2O4. Inelastic neutron scattering and magnetization studies reveal that the dynamical correlations at high temperatures are 1D. At lower temperature, these dynamical correlations become 2D. Surprisingly, the dynamical correlations condense into a quasi 2D Ising-like ordered state, making this a...

Spinel-type Li0.64Fe2.15Ge0.21O4, lithium diiron(III) germanium tetra-oxide, has been formed as a by-product during flux growth of an Li-Fe-Ge pyroxene-type material. In the title compound, lithium is ordered on the octa-hedral B sites, while Ge(4+) orders onto the tetra-hedral A sites, and iron distributes over both the octa-hedral and tetra-hedral sites, and is in the trivalent state as deter...

lini0.5co0.5vo4 has been successfully synthesized by tartate precursor combustion method using li2co3, co(no3)2.6h2o, ni(no3)2.6h2o and nh4vo3 as a starting materials in deionized water with the subsequent calcination at 450-600 oc for 12 h. the combustion and decomposition of tartate precursor were studied by tga and compared with tartaric acid. it found weight loss at 50-450 oc. the product s...

ten chromite ores from ophiolite complexes in se iran were analyzed mineralogically by xrd, chemically by xrf, and mineral chemistry by epma. the identified paragenesis of silicate minerals of chromite ores with the x-ray diffraction is pronounced differently. it consists of secondary phases formed as serpentine, cr-containing chlorite (kaemmererite), chromic garnet (uarovite) with preserved pa...

The transformation on heating LiCoMnO4, with a spinel structure, to LiCoMnO3, with a cation-disordered rock salt structure, accompanied by loss of 25% of the oxygen, has been followed using a combination of diffraction, microscopy and spectroscopy techniques. The transformation does not proceed by a topotactic mechanism, even though the spinel and rock salt phases have a similar, cubic close-pa...

Magnetic resonance imaging (MRI) is a powerful clinical imaging technique for the non-invasive diagnosis and posttherapy assessment of a variety of diseases. MRI contrast can be enhanced by the use of positive or negative contrast agents resulting in brighter (T1-weighted) or darker (T2-weighted) images, respectively. Superparamagnetic iron oxide (SPIO) nanoparticles are T2 contrast agents that...

ZnAl2O4 spinel powders were prepared using the Pechini or co-precipitation synthetic route and were then treated at different temperatures (600–1350 °C). These powders were characterised by X-ray diffraction, scanning electron microscopy (SEM), diffuse reflectance and luminescence measurements. SEM investigations and the X-ray patterns showed that the spinel crystallite size was dependent on th...