Materials Literature
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Thermodynamic perturbation theory is employed to derive analytical expressions for the equilibrium linear susceptibility and specific heat of lattices of anisotropic classical spins weakly coupled by the dipole-dipole interaction. The calculation is carried out to the second order in the coupling constant over the tem…
Theoretical study of graphite (graphene) edge is done. The most stable edge orientation is calculated to be a zigzag [110] edge. Possible applications of the result to the formation of different graphitic structures are discussed.
We present a theory of deformation potential carrier scattering of two-dimensional electron gases from the strain fields surrounding dislocations. The results are applied to study the transport characteristics in III-V nitride two-dimensional electron gases in Al(Ga)N/GaN quantum wells. A hypothetical charged core has…
We study the piezoresistive response and its anisotropy for a bond-percolation model of granular metals. Both effective-medium results and numerical Monte Carlo calculations of finite simple-cubic networks show that the piezoresistive anisotropy is a strongly dependent function of bond probability p and of bond conduc…
The temperature evolution of the infrared powder spectra of lithium tetraborate Li 2 B 4 O 7 has been measured in the infrared region 50-1600 cm -1 and over a temperature range between 20 K and 680 K. In contrast to the sharp B-O bands, the Li-related bands in the region between 300 cm -1 and 510 cm -1 are rather broa…
Onconase, a member of the RNase A superfamily, is a potent antitumor agent which is undergoing phase III clinical trials as an antitumor drug. We have recently shown that onconase is an unusually stable protein. Furthermore, the protein is resistant to the action of proteases, which could influence its use as a drug,…
Two Auger electrons, one very slow, one fast, have been detected in coincidence following near threshold 4d photoionization of the Xe atom. The distribution in the energy the two electrons share has been measured for the first time revealing the presence of post-collision interaction effects that provide unique inform…
Neutron powder diffraction data, collected over the temperature range 10-810 K, have been analysed in order to study the ferroelectric-paraelectric transition in the ferroelectric compound PbHf 0.2 Ti 0.8 O 3 . This transition appears at 670 K between the low-temperature tetragonal phase and the high-temperature cubic…
Photooxidation of β -carotene and canthaxanthin in mesoporous MCM-41, Ni-MCM-41, and Al-MCM-41 molecular sieves was studied by 9−220 GHz electron paramagnetic resonance (EPR) and 9 GHz electron nuclear double resonance (ENDOR). X-ray powder diffraction (XRD) measurements established that the MCM-41 pore size (33 Å) wa…
Abstract The double melting behavior of poly(butylene terephthalate) (PBT) was studied with differential scanning calorimetry (DSC) and wide‐angle X‐ray analysis. DSC melting curves of melt‐crystallized PBT samples, which we prepared by cooling from the melt (250 °C) at various cooling rates, showed two endothermic pe…
The cytotoxicity of a unimolecular polymeric micelle (1) and its degradation products was assessed by cell proliferation and viability with L929 mouse areolar/adipose fibroblasts. Polymer 1 and poly(ethylene glycol) (PEG) were diluted to concentrations from 10(-4) to 10(-6) M in culture media, whereas the degradation…
With on- and off- resonant excitation photons, spin-resolved Auger electron spectra of epitaxial CrO$_{2}$ thin films show an experimental evidence of the spin-selective KLL Auger decay. The on-resonance O KLL Auger electrons are found to be highly spin-polarized, while the off-resonance ones with almost zero spin pol…
The experimentally observed ferromagnetism in MgB2 in the normal state is attributed to micro phase separated inclusions of iron. This magnetic character is also observed when the iron content of the samples is reduced below 20 micro-g/g, however in these samples the diamagnetism of MgB2 is apparent and is measured. I…
Sonochemical decomposition of Fe(CO) 5 was carried out in the presence of different surfactants. The reactions give stable colloids of undecenoate, dodecyl sulfonate, and octyl phosphonate coated Fe 2 O 3 nanoparticles of 5−16 nm in diameter. The ionic binding of the surfactants to the nanoparticle surfaces was confir…
Efficient recognition of DNA is a prerequisite for the development of biological effectors, including transcription and translation regulators, transfection vectors, and DNA sensors. To provide an effective scaffold for multivalent interactions with DNA, we have fabricated mixed monolayer protected gold clusters (MMPC…
A large magnetic entropy change about twice as high as that of pure gadolinium metal near room temperature has been discovered in manganese perovskites La 0.837 Ca 0.098 Na 0.038 Mn 0.987 O 3.00 (8.3 J·kg -1 ·K -1 , at 256 K) and La 0.822 Ca 0.096 K 0.043 Mn 0.974 O 3.00 (6.8 J·kg -1 ·K -1 , at 265 K) under a magnetic…
Changes in the atomic structure and optical properties of amorphous films in the As-Se system upon annealing have been studied on films prepared by thermal evaporation in a vacuum and by RF ion-plasma sputtering. The annealing modifies the atomic structure of the films and shifts their optical absorption edge. Changes…
Micro-Raman study in the temperature range of 70-575 K was performed to investigate the overlap of the basic phase transitions in barium titanate ceramics and single crystals of low Zr concentration. The possibilities of stress and grain size effects that are crucial for the optimization and reproducibility of the pro…
Micrometer-sized carbon tubes and their regularly assembled structures can be easily prepared via the pyrolysis of composite fibers consisting of a poly(ethylene terephthalate) (PET) core and a conducting polymer skin layer, such as polypyrrole (PPy). Using this new chemical approach, the diameter, wall thickness, and…
Terfenol-D particulate composites have been fabricated with and without a preferred crystal orientation of the particles. A 25% volume fraction polymer matrix composite was fabricated in a magnetic field using geometric anisotropy to orient needle shaped particles with long axis [112] orientation along the length of t…