Materials Literature
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We study numerically the energetics and atomic mechanisms of misfit dislocation nucleation and stress relaxation in a two-dimensional atomistic model of strained epitaxial layers on a substrate with lattice misfit. Relaxation processes from coherent to incoherent states for different transition paths are studied using…
Photo-physical and nonlinear-optical properties of a new amphiphilic conjugated polymer: hydroxylated pyridyl para-phenylene (Py-PhPPP) both in CH2Cl2 solution and in thin films have been investigated. By using Z-scan technique with nanosecond laser pulses of wavelengths ranging from 430 to 600 nm, the large nonlinear…
A wide emission band in the region of 425 nm is observed in all the examined crystals at photo and ionising irradiation. Maximum of the complex luminescence band is observed at 410 nm at 350 K and at 450 nm at 85 K. The shift of the peak of the band envelope towards shorter wavelengths as the temperature increases is…
Spatial uniformity of electron emission from velvet cathodes has been measured by observing the distribution of electrons hitting the anode in a planar high-voltage diode. It is shown that unless all electrons move parallel to the diode axis, the electron distribution measured at the anode does not represent the catho…
A study of the visible photoluminescence in single-crystal NiO and Ni<sub>c</sub>Mg<sub>1-c</sub>O (c = 0.99, 0.98 and 0.95) solid solutions is presented for the first time. Two wide luminescence bands, peaked at approximately 12000 cm<sup>-1</sup> and approximately 18500 cm<sup>-1</sup>, were observed. The dependence…
Poly(aspartic acid) (PAA) hydrolase-2 was purified from crude soluble cellular extracts of Sphingomonas sp. KT-1 (JCM10459) and characterized to elucidate the mechanism of alpha,beta-poly(d,l-aspartic acid) (tPAA) biodegradation. The molecular mass of PAA hydrolase-2 was 42 kDa, and the isoelectric point was 9.6. The…
We have fabricated La0.8Ba0.2MnO3 ultrathin films with an atomically flat surface and have systematically investigated the magnetism for film thickness dependence. The 20-nm-thick film showed a maximum peak of TC (310 K). It was found that even the 5-nm-thick film showed a TC of 290 K near room temperature, which open…
The temperature and frequency dependent ionic conductivity in ${\mathrm{Li}}_{x}{\mathrm{Rb}}_{1\ensuremath{-}x}{\mathrm{PO}}_{3}$ glasses has been studied using dielectric spectroscopy. The dc conductivity decreases by more than six orders of magnitude on mixing the alkali ions in the glass structure, that is, a stro…
High-quality ZnO nanocrystals have been fabricated by zinc ion implantation (160 keV, 1×1017 ions/cm2) into a CaF2(111) single-crystal substrate followed by thermal annealing from 300 to 700 °C. X-ray diffraction results show that ZnO nanocrystals in CaF2(111) substrate have a (002) preferred orientation. The average…
Vertically aligned carbon nanofibers (VACNFs) have been grown using a low-pressure, plasma-enhanced, chemical vapor deposition process. The nanofibers are grown from a nickel catalyst that can be patterned to form arrays of individual, isolated VACNFs. The fibers are grown at pressures below 100 mTorr, using an induct…
A new methodology for preparing heteroporphyrin arrays in aqueous solution has been presented. The present method is based on the extremely strong ability of heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TMe-beta-CD) to include 5,10,15,20-tetrakis(p-substituted-phenyl)porphyrins (Por) affording trans-type 1:2 comple…
In order to understand the effects of plasma parameters on the nanotube formation and further controlled growth, we have investigated the optimal growth condition using a rf plasma-enhanced chemical vapor deposition method. The magnetic field introduced for a magnetron discharge enhances the nanotube growth as a resul…
The dynamics of polarization switching have been investigated over extremely broad time (10−8&lt;t&lt;102 s) and field ranges for various modified Pb-based perovskite ferroelectrics. The results unambiguously demonstrate the presence of extremely broad relaxation time distributions for switching, which can ext…
The paraelectric–ferroelectric phase transition in the [(CH 3 ) 3 NH] 3 [Sb 2 Cl 9(1− x ) Br 9 x ] (TMACBA) mixed crystals is investigated by the differential scanning calorimetry, dilatometric and dielectric methods. The phase transition is found at 363.5, 362.7, 360.5 and 350.9 K (on cooling) for TMACBA crystals wit…
Neutron diffraction was used to measure the total structure factors for several rare-earth ion ${R}^{3+}$ $({\mathrm{La}}^{3+}$ or ${\mathrm{Ce}}^{3+})$ phosphate glasses with composition close to $R{\mathrm{Al}}_{0.35}{\mathrm{P}}_{3.24}{\mathrm{O}}_{10.12}.$ By assuming isomorphic structures, difference function met…
Antibody-directed enzyme prodrug therapy (ADEPT) is a recent development for a selective treatment of cancer, based on site-directed formation at the surface of malignant cells of cytotoxic compounds from non-toxic prodrugs with a conjugate of an appropriate enzyme and a monoclonal antibody which binds to tumour-assoc…
The crystal structures of lanthanum gallate perovskite compounds, LaGaO 3, LaGa 0.8 Mg 0.2 O 2.9, and La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 2.8 which is well-known as a superior oxide ion conductor, have been analyzed by neutron powder diffraction to clarify the effect of the substitutions on the perovskite structures. The cr…
The chirality effect of an opened-end single-wall carbon nanotube on field emission is studied by using the tunneling theory with the tight-binding approximation. The characteristic of the emission-current line density versus field is found to be dependence on the chirality of nanotubes. A metallic tube has a line den…
The results of an in-depth study of 1 nm thick individual clay sheets by atomic force microscopy (AFM) are presented. Several techniques have been employed, including lateral force microscopy (LFM) and force modulation microscopy (FMM). The individual clay sheets, also referred to as clay nanoplatelets in the literatu…
ZnSeO alloy was grown by molecular-beam epitaxy up to 1.3% O composition on GaAs substrate using rf plasma. The crystal structure of epitaxial ZnSeO alloy was zinc-blende. O composition was estimated by a strain-free lattice constant. No phase separation was observed by in situ reflection high-energy electron diffract…