We report the first occurrence of a natural quasicrystal with decagonal symmetry. The quasicrystal, with composition Al71Ni24Fe5, was discovered in the Khatyrka meteorite, a recently described CV3 carbonaceous chondrite. Icosahedrite, Al63Cu24Fe13, the first natural quasicrystal to be identified, was found in the same meteorite. The new quasicrystal was found associated with steinhardtite (Al38...

We report an adjustable magnetic resonance frequency from 1.45 to 2.54 GHz for NiFe2O4 nanoparticles which were prepared by a sol-gel process. X-ray diffraction and scanning electron microscopy results indicate that the samples are polycrystalline nanoparticles, and the size of the particles increases obviously with the thermal treatment temperature. The consequence of the surface composition s...

Appropriate addition of CuO/V2O5 and the reduction of the granularity of the raw materials particle decrease the sintering temperature of NiZn ferrite from 1200 degrees C to 930 degrees C. Furthermore, the magnetic properties of the NiZn ferrite prepared at low temperature of 930 degrees C is superior to that of the NiZn ferrite prepared by sintering at high temperature of 1200 degrees C becaus...

Nickel ferrites have been extensively studied due to their numerous applications in electronic devices, microwave adsorbents, corrosion protectors, magnetic fluids and catalysts [1-5], among others. Nickel ferrite is a soft material with inverted spinel with the tetrahedral site (A) occupied by Fe and the octahedral site occupied by Fe and Ni. It is applied to devices that require easy magnetiz...

Conducting polymer/ferrite nanocomposites with an organized structure provide a new functional hybrid between organic and inorganic materials. The most popular among the conductive polymers is the polyaniline (PANI) due to its wide application in different fields. In the present work nickel ferrite (NiFe2O4) nanoparticles were prepared by sol-gel citrate-nitrate method with an average size of 2...

nanometric carbid silicon (sic) supported monometallic and bimetallic catalysts containing fe, co, ni transition metals were prepared by wet impregnation method. multiwall carbon nanotubes (mwcnts) were synthesized over the prepared catalysts from catalytic decomposition of acetylene at 850°c by thermal chemical vapor deposition (tcvd) technique. the synthesized nanomaterials (catalysts and cnt...

pure and zno-doped ni0.1co0.9fe2o4 catalyst were prepared by co-precipitation method and thermal decomposition in air calcinated at 400-700°c and that treated with different amounts of zinc nitrate (0.46-2.25 w% zno). x-ray powder diffractometry, scanning electron microscopy (sem) and bet analysis of nitrogen adsorption isotherms investigated the crystalline bulk structure and the surface area ...

INTRODUCTION Stainless steel welds characteristically consist of a two-phase austenite plus ferrite microstructure. Ferrite levels may vary from a few percent in austenitic stainless steel welds to more than 50% in duplex stainless steel welds. The ability to predict the ferrite content in these welds is essential for many reasons. To a large extent, the final ferrite content determines a weldm...