An equiatomic FeCoCrNi high-entropy alloy with a face-centered cubic structure was fabricated by a powder metallurgy route, and then processed by high-pressure torsion. Detailed microscopy investigations revealed that grain refinement from coarse grains to nanocrystalline grains occurred mainly via concurrent nanoband (NB) subdivision and deformation twinning. NB-NB, twin-NB and twin-twin inter...

A comparison of the X-ray powder diffraction (XRPD) patterns of face-centered cubic silver with twin faults simulated with the DIFFaX and MAUD computer programs is presented. MAUD was used to refine the DIFFaX-simulated patterns to determine systematic differences between these simulation programs. The results indicated the Warren model of twin faults is applicable for fault probabilities <10% ...

Ultraviolet and blue light were obtained by nonlinear frequency conversion in a random laser (RL) based on Nd0.10Y0.90Al3(BO3)4 nanocrystalline powder. RL operation at 1062 nm, due to the (4)F3/2 → (4)I11/2 transition of neodymium ions (Nd(3+)), was achieved by exciting the Nd(3+) with a tunable beam from 680 to 920 nm covering the ground state absorption transitions to the (4)F9/2, ((4)F7/2,(4...

Dielectric spectroscopy was applied to porous nanocrystalline Na0.5K0.5NbO3 (NKN) ceramic green body, wherein influences of percolation effect and water adsorption at pore surface of the ceramic green body on dielectric response were examined over wide temperature (150 to 450 K) and frequency (100 Hz to 1 MHz) ranges. Dielectric permittivity of the ceramic green body is about 2–3 orders of magn...

We report on magnetorheological finishing (MRF) spotting experiments performed on glasses and ceramics using a zirconia-coated carbonyl-iron (CI)-particle-based magnetorheological (MR) fluid. The zirconia-coated magnetic CI particles were prepared via sol-gel synthesis in kilogram quantities. The coating layer was approximately 50-100 nm thick, faceted in surface structure, and well adhered. Co...

in this paper cufe2o4, nanocrystalline powders were prepared. also, the supported cu ferrite was obtained by impregnation of the supports with cu and fe nitrates solutions, for calcination temperature 450 ºc. the samples were characterized by x-ray powder diffraction (xrd) and fourier transform-infrared spectroscopy (ft-ir). photocatalytic degradation of acid red 206 in water was studied. cufe2...

A bifunctional hybrid nanomaterial, which can show magnetic and luminescent properties, was obtained. A magnetic phase was synthesized as a core/shell type composite. Nanocrystalline magnetite, Fe(3)O(4) was used as the core and was encapsulated in a silica shell. The luminescent phase was GdPO(4) doped with Eu(3+) ions, as the emitter. The investigated materials were synthesized using a coprec...

Zirconia-coated nanodiamond (ZrO₂/ND) electrode material was successfully prepared by one-step isothermal hydrolyzing from ND-dispersed ZrOCl₂·8H₂O aqueous solution. High-resolution transmission electron microscopy reveals that a highly conformal and uniform ZrO₂ shell was deposited on NDs by this simple method. The coating obtained at 90 °C without further calcination was mainly composed of mo...

ZnO can be regarded as one of the most important metal oxide semiconductors for future applications. Similar to silicon in microelectronics, it is not only important to obtain nanoscale building blocks of ZnO, but also extraordinary purity has to be ensured. A new gas-phase approach to obtain size-selected, nanocrystalline ZnO particles is presented. The tetrameric alkyl-alkoxy zinc compound [C...

Mechanical alloying (MA) is a powder process that consists of repeated cold welding, fracturing, and rewelding particles in high-energy ball mill. This capable synthesizing different types non-equilibrium phases including supersaturated solid solutions, nanocrystalline materials, metallic glasses, high-entropy alloys, several others. MA'd materials have found many applications. The present arti...