Materials Literature
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The domain structures and dislocations in epitaxial thin films of La0.7Ca0.3MnO3 grown on SrTiO3 substrates by pulsed laser deposition were investigated using Bragg-contrast diffraction and high-resolution transmission electron microscopy. It revealed that the films contained the 1/2[100]o and 1/2[10-1]o types partial…
Thermodynamic properties of Ne, Ar, Kr, and Xe adsorbed on an Al-Ni-Co quasicrystalline surface (QC) are studied with Grand Canonical Monte Carlo by employing Lennard-Jones interactions with parameter values derived from experiments and traditional combining rules. In all the gas/QC systems, a layer-by-layer film grow…
The effects of local B-cation (Ti, Zr) distribution and octahedral tilting on the pre-edge structure in the Ti x-ray absorption $K$-spectra of the ${\mathrm{CaTi}}_{1\ensuremath{-}x}{\mathrm{Zr}}_{x}{\mathrm{O}}_{3}$ perovskite solid solutions were investigated. Experimental spectra for the disordered ${\mathrm{CaTi}}…
A combination of high-resolution x-ray diffraction and a technique of x-ray standing-wave fluorescence at grazing incidence is employed to study the structure of a (Ga,Mn)As-diluted magnetic semiconductor and its changes during post-growth annealing steps. We find that the film is formed by a uniform, single-crystallo…
We have studied the pressure effect on magnetostriction, both in the $ab$-plane and along the c-axis, of a (La,Pr)$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$ bilayered manganite single crystal over the temperature region where the field-induced ferromagnetic metal (FMM) transition takes place. For comparison, we have also exami…
The authors report on the functionalization of multiferroic BiFeO3 epitaxial films for spintronics. A first example is provided by the use of ultrathin layers of BiFeO3 as tunnel barriers in magnetic tunnel junctions with La2∕3Sr1∕3MnO3 and Co electrodes. In such structures, a positive tunnel magnetoresistance up to 3…
Molecular dynamics simulations are used to model the thermal properties of a fluid containing solid nanoparticles (nanofluid). The flexibility of molecular simulation allows us to consider the effects of particle mass, particle-particle and particle-fluid interaction and that of the spatial distribution of the particl…
The ac conductivity of CaCu3Ti4O12 ceramics associated with electrical charge carrier motion (ions or vacancies) was investigated as a function of frequency at different temperatures. The long range migration of charge carriers within the ceramic is restricted by two kinds of insulating barriers, namely, grain boundar…
We analyze the origin of ferromagnetism as a result of carrier mediation in diluted magnetic oxide semiconductors in the light of the experimental evidence reported in the literature. We propose that a combination of percolation of magnetic polarons at lower temperature and Ruderman-Kittel-Kasuya-Yosida ferromagnetism…
We report a first-principles study on the geometric, electronic, and magnetic properties of V-doped anatase $\mathrm{Ti}{\mathrm{O}}_{2}$. The $\mathrm{DFT}+U$ (Hubbard coefficient) approach predicts semiconductor band structures for ${\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{V}}_{x}{\mathrm{O}}_{2}$ ($x=6.25%$ and 12.…
The temperature dependencies of magnetic susceptibility in temperature range 4.2-250 K along the principal magnetic axes as well as frequency-field dependence EPR spectrum at helium temperature in basic plane was studied. It is found that ground state of CsPr(MoO4)2, is the quasi-doublet. The experimental values of g-…
We report on a study of (001) oriented fcc Fe-Ni alloy surfaces which combines first-principles calculations and low-temperature STM experiments. Density functional theory calculations show that Fe-Ni alloy surfaces are buckled with the Fe atoms slightly shifted outwards and the Ni atoms inwards. This is consistent wi…
Here we report a new class of molecular hydrogelators based on the conjugates of dipeptide and (naphthalen-2-yloxy)acetic acid. They form hydrogels efficiently—the lowest concentration for them to gel water is 0.07 wt%. Two hydrogelators show the ability to form helical nanofibers within the hydrogels, and the chirali…
We show in principle how to cloak a region of space to make its contents classically invisible or transparent to waves. The method uses sensors and active sources near the surface of the region, and could operate over broad bandwidths. A general expression is given for calculating the necessary sources, and explicit,…
Abstract Rigid polyurethane (PU) foams were prepared using three North American seed oil starting materials. Polyol with terminal primary hydroxyl groups synthesized from canola oil by ozonolysis and hydrogenation based technology, commercially available soybean based polyol and crude castor oil were reacted with arom…
Polycrystalline Bi1−xNdxFeO3 (x=0–0.15) thin films were prepared on (111) Pt∕Ti∕SiO2∕Si substrates via metal organic deposition method. The effect of Nd dopant on the structural, electric, and magnetic properties was studied. It was found that the ferroelectric polarization and saturation magnetization of the films we…
Magnetic nanoparticles exhibit unique nanoscale properties and their utilization for various magnetic systems is of significant interest. Especially, heterostructured magnetic nanoparticles are emerging as next-generation materials due to their synergistically enhanced magnetism and potential multifunctionalities. Her…
The authors have recently observed a giant electrocaloric effect (12K in 25V) in 350nm sol-gel PbZr0.95Ti0.05O3 films near the ferroelectric Curie temperature of 242°C. Here the authors demonstrate a giant electrocaloric effect (5K in 25V) in 260nm sol-gel films of the relaxor ferroelectric 0.9PbMg1∕3Nb2∕3O3–0.1PbTiO3…
BACKGROUND: The mechanisms governing the correlation between exposure to ultrafine particles and the increased incidence of cardiovascular disease remain unknown. Ultrafine particles appear to cross the pulmonary epithelial barrier into the bloodstream, raising the possibility of direct contact with the vascular endot…
Morphology-controlled nano- and microcrystals of ZnO (see figure) with different ratios of polar to nonpolar faces were synthesized through a soft-solution process. With these crystals, it is clearly demonstrated that a ZnO nanoplate with a large population of polar Zn(0001) faces is the most photocatalytically active…